diff --git a/vendor/golang.org/x/text/internal/colltab/collelem.go b/vendor/golang.org/x/text/internal/colltab/collelem.go
new file mode 100644
index 0000000..2855589
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/collelem.go
@@ -0,0 +1,371 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package colltab
+
+import (
+	"fmt"
+	"unicode"
+)
+
+// Level identifies the collation comparison level.
+// The primary level corresponds to the basic sorting of text.
+// The secondary level corresponds to accents and related linguistic elements.
+// The tertiary level corresponds to casing and related concepts.
+// The quaternary level is derived from the other levels by the
+// various algorithms for handling variable elements.
+type Level int
+
+const (
+	Primary Level = iota
+	Secondary
+	Tertiary
+	Quaternary
+	Identity
+
+	NumLevels
+)
+
+const (
+	defaultSecondary = 0x20
+	defaultTertiary  = 0x2
+	maxTertiary      = 0x1F
+	MaxQuaternary    = 0x1FFFFF // 21 bits.
+)
+
+// Elem is a representation of a collation element. This API provides ways to encode
+// and decode Elems. Implementations of collation tables may use values greater
+// or equal to PrivateUse for their own purposes.  However, these should never be
+// returned by AppendNext.
+type Elem uint32
+
+const (
+	maxCE       Elem = 0xAFFFFFFF
+	PrivateUse       = minContract
+	minContract      = 0xC0000000
+	maxContract      = 0xDFFFFFFF
+	minExpand        = 0xE0000000
+	maxExpand        = 0xEFFFFFFF
+	minDecomp        = 0xF0000000
+)
+
+type ceType int
+
+const (
+	ceNormal           ceType = iota // ceNormal includes implicits (ce == 0)
+	ceContractionIndex               // rune can be a start of a contraction
+	ceExpansionIndex                 // rune expands into a sequence of collation elements
+	ceDecompose                      // rune expands using NFKC decomposition
+)
+
+func (ce Elem) ctype() ceType {
+	if ce <= maxCE {
+		return ceNormal
+	}
+	if ce <= maxContract {
+		return ceContractionIndex
+	} else {
+		if ce <= maxExpand {
+			return ceExpansionIndex
+		}
+		return ceDecompose
+	}
+	panic("should not reach here")
+	return ceType(-1)
+}
+
+// For normal collation elements, we assume that a collation element either has
+// a primary or non-default secondary value, not both.
+// Collation elements with a primary value are of the form
+// 01pppppp pppppppp ppppppp0 ssssssss
+//   - p* is primary collation value
+//   - s* is the secondary collation value
+// 00pppppp pppppppp ppppppps sssttttt, where
+//   - p* is primary collation value
+//   - s* offset of secondary from default value.
+//   - t* is the tertiary collation value
+// 100ttttt cccccccc pppppppp pppppppp
+//   - t* is the tertiar collation value
+//   - c* is the canonical combining class
+//   - p* is the primary collation value
+// Collation elements with a secondary value are of the form
+// 1010cccc ccccssss ssssssss tttttttt, where
+//   - c* is the canonical combining class
+//   - s* is the secondary collation value
+//   - t* is the tertiary collation value
+// 11qqqqqq qqqqqqqq qqqqqqq0 00000000
+//   - q* quaternary value
+const (
+	ceTypeMask              = 0xC0000000
+	ceTypeMaskExt           = 0xE0000000
+	ceIgnoreMask            = 0xF00FFFFF
+	ceType1                 = 0x40000000
+	ceType2                 = 0x00000000
+	ceType3or4              = 0x80000000
+	ceType4                 = 0xA0000000
+	ceTypeQ                 = 0xC0000000
+	Ignore                  = ceType4
+	firstNonPrimary         = 0x80000000
+	lastSpecialPrimary      = 0xA0000000
+	secondaryMask           = 0x80000000
+	hasTertiaryMask         = 0x40000000
+	primaryValueMask        = 0x3FFFFE00
+	maxPrimaryBits          = 21
+	compactPrimaryBits      = 16
+	maxSecondaryBits        = 12
+	maxTertiaryBits         = 8
+	maxCCCBits              = 8
+	maxSecondaryCompactBits = 8
+	maxSecondaryDiffBits    = 4
+	maxTertiaryCompactBits  = 5
+	primaryShift            = 9
+	compactSecondaryShift   = 5
+	minCompactSecondary     = defaultSecondary - 4
+)
+
+func makeImplicitCE(primary int) Elem {
+	return ceType1 | Elem(primary<<primaryShift) | defaultSecondary
+}
+
+// MakeElem returns an Elem for the given values.  It will return an error
+// if the given combination of values is invalid.
+func MakeElem(primary, secondary, tertiary int, ccc uint8) (Elem, error) {
+	if w := primary; w >= 1<<maxPrimaryBits || w < 0 {
+		return 0, fmt.Errorf("makeCE: primary weight out of bounds: %x >= %x", w, 1<<maxPrimaryBits)
+	}
+	if w := secondary; w >= 1<<maxSecondaryBits || w < 0 {
+		return 0, fmt.Errorf("makeCE: secondary weight out of bounds: %x >= %x", w, 1<<maxSecondaryBits)
+	}
+	if w := tertiary; w >= 1<<maxTertiaryBits || w < 0 {
+		return 0, fmt.Errorf("makeCE: tertiary weight out of bounds: %x >= %x", w, 1<<maxTertiaryBits)
+	}
+	ce := Elem(0)
+	if primary != 0 {
+		if ccc != 0 {
+			if primary >= 1<<compactPrimaryBits {
+				return 0, fmt.Errorf("makeCE: primary weight with non-zero CCC out of bounds: %x >= %x", primary, 1<<compactPrimaryBits)
+			}
+			if secondary != defaultSecondary {
+				return 0, fmt.Errorf("makeCE: cannot combine non-default secondary value (%x) with non-zero CCC (%x)", secondary, ccc)
+			}
+			ce = Elem(tertiary << (compactPrimaryBits + maxCCCBits))
+			ce |= Elem(ccc) << compactPrimaryBits
+			ce |= Elem(primary)
+			ce |= ceType3or4
+		} else if tertiary == defaultTertiary {
+			if secondary >= 1<<maxSecondaryCompactBits {
+				return 0, fmt.Errorf("makeCE: secondary weight with non-zero primary out of bounds: %x >= %x", secondary, 1<<maxSecondaryCompactBits)
+			}
+			ce = Elem(primary<<(maxSecondaryCompactBits+1) + secondary)
+			ce |= ceType1
+		} else {
+			d := secondary - defaultSecondary + maxSecondaryDiffBits
+			if d >= 1<<maxSecondaryDiffBits || d < 0 {
+				return 0, fmt.Errorf("makeCE: secondary weight diff out of bounds: %x < 0 || %x > %x", d, d, 1<<maxSecondaryDiffBits)
+			}
+			if tertiary >= 1<<maxTertiaryCompactBits {
+				return 0, fmt.Errorf("makeCE: tertiary weight with non-zero primary out of bounds: %x > %x", tertiary, 1<<maxTertiaryCompactBits)
+			}
+			ce = Elem(primary<<maxSecondaryDiffBits + d)
+			ce = ce<<maxTertiaryCompactBits + Elem(tertiary)
+		}
+	} else {
+		ce = Elem(secondary<<maxTertiaryBits + tertiary)
+		ce += Elem(ccc) << (maxSecondaryBits + maxTertiaryBits)
+		ce |= ceType4
+	}
+	return ce, nil
+}
+
+// MakeQuaternary returns an Elem with the given quaternary value.
+func MakeQuaternary(v int) Elem {
+	return ceTypeQ | Elem(v<<primaryShift)
+}
+
+// Mask sets weights for any level smaller than l to 0.
+// The resulting Elem can be used to test for equality with
+// other Elems to which the same mask has been applied.
+func (ce Elem) Mask(l Level) uint32 {
+	return 0
+}
+
+// CCC returns the canonical combining class associated with the underlying character,
+// if applicable, or 0 otherwise.
+func (ce Elem) CCC() uint8 {
+	if ce&ceType3or4 != 0 {
+		if ce&ceType4 == ceType3or4 {
+			return uint8(ce >> 16)
+		}
+		return uint8(ce >> 20)
+	}
+	return 0
+}
+
+// Primary returns the primary collation weight for ce.
+func (ce Elem) Primary() int {
+	if ce >= firstNonPrimary {
+		if ce > lastSpecialPrimary {
+			return 0
+		}
+		return int(uint16(ce))
+	}
+	return int(ce&primaryValueMask) >> primaryShift
+}
+
+// Secondary returns the secondary collation weight for ce.
+func (ce Elem) Secondary() int {
+	switch ce & ceTypeMask {
+	case ceType1:
+		return int(uint8(ce))
+	case ceType2:
+		return minCompactSecondary + int((ce>>compactSecondaryShift)&0xF)
+	case ceType3or4:
+		if ce < ceType4 {
+			return defaultSecondary
+		}
+		return int(ce>>8) & 0xFFF
+	case ceTypeQ:
+		return 0
+	}
+	panic("should not reach here")
+}
+
+// Tertiary returns the tertiary collation weight for ce.
+func (ce Elem) Tertiary() uint8 {
+	if ce&hasTertiaryMask == 0 {
+		if ce&ceType3or4 == 0 {
+			return uint8(ce & 0x1F)
+		}
+		if ce&ceType4 == ceType4 {
+			return uint8(ce)
+		}
+		return uint8(ce>>24) & 0x1F // type 2
+	} else if ce&ceTypeMask == ceType1 {
+		return defaultTertiary
+	}
+	// ce is a quaternary value.
+	return 0
+}
+
+func (ce Elem) updateTertiary(t uint8) Elem {
+	if ce&ceTypeMask == ceType1 {
+		// convert to type 4
+		nce := ce & primaryValueMask
+		nce |= Elem(uint8(ce)-minCompactSecondary) << compactSecondaryShift
+		ce = nce
+	} else if ce&ceTypeMaskExt == ceType3or4 {
+		ce &= ^Elem(maxTertiary << 24)
+		return ce | (Elem(t) << 24)
+	} else {
+		// type 2 or 4
+		ce &= ^Elem(maxTertiary)
+	}
+	return ce | Elem(t)
+}
+
+// Quaternary returns the quaternary value if explicitly specified,
+// 0 if ce == Ignore, or MaxQuaternary otherwise.
+// Quaternary values are used only for shifted variants.
+func (ce Elem) Quaternary() int {
+	if ce&ceTypeMask == ceTypeQ {
+		return int(ce&primaryValueMask) >> primaryShift
+	} else if ce&ceIgnoreMask == Ignore {
+		return 0
+	}
+	return MaxQuaternary
+}
+
+// Weight returns the collation weight for the given level.
+func (ce Elem) Weight(l Level) int {
+	switch l {
+	case Primary:
+		return ce.Primary()
+	case Secondary:
+		return ce.Secondary()
+	case Tertiary:
+		return int(ce.Tertiary())
+	case Quaternary:
+		return ce.Quaternary()
+	}
+	return 0 // return 0 (ignore) for undefined levels.
+}
+
+// For contractions, collation elements are of the form
+// 110bbbbb bbbbbbbb iiiiiiii iiiinnnn, where
+//   - n* is the size of the first node in the contraction trie.
+//   - i* is the index of the first node in the contraction trie.
+//   - b* is the offset into the contraction collation element table.
+// See contract.go for details on the contraction trie.
+const (
+	maxNBits              = 4
+	maxTrieIndexBits      = 12
+	maxContractOffsetBits = 13
+)
+
+func splitContractIndex(ce Elem) (index, n, offset int) {
+	n = int(ce & (1<<maxNBits - 1))
+	ce >>= maxNBits
+	index = int(ce & (1<<maxTrieIndexBits - 1))
+	ce >>= maxTrieIndexBits
+	offset = int(ce & (1<<maxContractOffsetBits - 1))
+	return
+}
+
+// For expansions, Elems are of the form 11100000 00000000 bbbbbbbb bbbbbbbb,
+// where b* is the index into the expansion sequence table.
+const maxExpandIndexBits = 16
+
+func splitExpandIndex(ce Elem) (index int) {
+	return int(uint16(ce))
+}
+
+// Some runes can be expanded using NFKD decomposition. Instead of storing the full
+// sequence of collation elements, we decompose the rune and lookup the collation
+// elements for each rune in the decomposition and modify the tertiary weights.
+// The Elem, in this case, is of the form 11110000 00000000 wwwwwwww vvvvvvvv, where
+//   - v* is the replacement tertiary weight for the first rune,
+//   - w* is the replacement tertiary weight for the second rune,
+// Tertiary weights of subsequent runes should be replaced with maxTertiary.
+// See http://www.unicode.org/reports/tr10/#Compatibility_Decompositions for more details.
+func splitDecompose(ce Elem) (t1, t2 uint8) {
+	return uint8(ce), uint8(ce >> 8)
+}
+
+const (
+	// These constants were taken from http://www.unicode.org/versions/Unicode6.0.0/ch12.pdf.
+	minUnified       rune = 0x4E00
+	maxUnified            = 0x9FFF
+	minCompatibility      = 0xF900
+	maxCompatibility      = 0xFAFF
+	minRare               = 0x3400
+	maxRare               = 0x4DBF
+)
+const (
+	commonUnifiedOffset = 0x10000
+	rareUnifiedOffset   = 0x20000 // largest rune in common is U+FAFF
+	otherOffset         = 0x50000 // largest rune in rare is U+2FA1D
+	illegalOffset       = otherOffset + int(unicode.MaxRune)
+	maxPrimary          = illegalOffset + 1
+)
+
+// implicitPrimary returns the primary weight for the a rune
+// for which there is no entry for the rune in the collation table.
+// We take a different approach from the one specified in
+// http://unicode.org/reports/tr10/#Implicit_Weights,
+// but preserve the resulting relative ordering of the runes.
+func implicitPrimary(r rune) int {
+	if unicode.Is(unicode.Ideographic, r) {
+		if r >= minUnified && r <= maxUnified {
+			// The most common case for CJK.
+			return int(r) + commonUnifiedOffset
+		}
+		if r >= minCompatibility && r <= maxCompatibility {
+			// This will typically not hit. The DUCET explicitly specifies mappings
+			// for all characters that do not decompose.
+			return int(r) + commonUnifiedOffset
+		}
+		return int(r) + rareUnifiedOffset
+	}
+	return int(r) + otherOffset
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/colltab.go b/vendor/golang.org/x/text/internal/colltab/colltab.go
new file mode 100644
index 0000000..02f2247
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/colltab.go
@@ -0,0 +1,105 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package colltab contains functionality related to collation tables.
+// It is only to be used by the collate and search packages.
+package colltab // import "golang.org/x/text/internal/colltab"
+
+import (
+	"sort"
+
+	"golang.org/x/text/language"
+)
+
+// MatchLang finds the index of t in tags, using a matching algorithm used for
+// collation and search. tags[0] must be language.Und, the remaining tags should
+// be sorted alphabetically.
+//
+// Language matching for collation and search is different from the matching
+// defined by language.Matcher: the (inferred) base language must be an exact
+// match for the relevant fields. For example, "gsw" should not match "de".
+// Also the parent relation is different, as a parent may have a different
+// script. So usually the parent of zh-Hant is und, whereas for MatchLang it is
+// zh.
+func MatchLang(t language.Tag, tags []language.Tag) int {
+	// Canonicalize the values, including collapsing macro languages.
+	t, _ = language.All.Canonicalize(t)
+
+	base, conf := t.Base()
+	// Estimate the base language, but only use high-confidence values.
+	if conf < language.High {
+		// The root locale supports "search" and "standard". We assume that any
+		// implementation will only use one of both.
+		return 0
+	}
+
+	// Maximize base and script and normalize the tag.
+	if _, s, r := t.Raw(); (r != language.Region{}) {
+		p, _ := language.Raw.Compose(base, s, r)
+		// Taking the parent forces the script to be maximized.
+		p = p.Parent()
+		// Add back region and extensions.
+		t, _ = language.Raw.Compose(p, r, t.Extensions())
+	} else {
+		// Set the maximized base language.
+		t, _ = language.Raw.Compose(base, s, t.Extensions())
+	}
+
+	// Find start index of the language tag.
+	start := 1 + sort.Search(len(tags)-1, func(i int) bool {
+		b, _, _ := tags[i+1].Raw()
+		return base.String() <= b.String()
+	})
+	if start < len(tags) {
+		if b, _, _ := tags[start].Raw(); b != base {
+			return 0
+		}
+	}
+
+	// Besides the base language, script and region, only the collation type and
+	// the custom variant defined in the 'u' extension are used to distinguish a
+	// locale.
+	// Strip all variants and extensions and add back the custom variant.
+	tdef, _ := language.Raw.Compose(t.Raw())
+	tdef, _ = tdef.SetTypeForKey("va", t.TypeForKey("va"))
+
+	// First search for a specialized collation type, if present.
+	try := []language.Tag{tdef}
+	if co := t.TypeForKey("co"); co != "" {
+		tco, _ := tdef.SetTypeForKey("co", co)
+		try = []language.Tag{tco, tdef}
+	}
+
+	for _, tx := range try {
+		for ; tx != language.Und; tx = parent(tx) {
+			for i, t := range tags[start:] {
+				if b, _, _ := t.Raw(); b != base {
+					break
+				}
+				if tx == t {
+					return start + i
+				}
+			}
+		}
+	}
+	return 0
+}
+
+// parent computes the structural parent. This means inheritance may change
+// script. So, unlike the CLDR parent, parent(zh-Hant) == zh.
+func parent(t language.Tag) language.Tag {
+	if t.TypeForKey("va") != "" {
+		t, _ = t.SetTypeForKey("va", "")
+		return t
+	}
+	result := language.Und
+	if b, s, r := t.Raw(); (r != language.Region{}) {
+		result, _ = language.Raw.Compose(b, s, t.Extensions())
+	} else if (s != language.Script{}) {
+		result, _ = language.Raw.Compose(b, t.Extensions())
+	} else if (b != language.Base{}) {
+		result, _ = language.Raw.Compose(t.Extensions())
+	}
+	return result
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/contract.go b/vendor/golang.org/x/text/internal/colltab/contract.go
new file mode 100644
index 0000000..25649d4
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/contract.go
@@ -0,0 +1,145 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package colltab
+
+import "unicode/utf8"
+
+// For a description of ContractTrieSet, see text/collate/build/contract.go.
+
+type ContractTrieSet []struct{ L, H, N, I uint8 }
+
+// ctScanner is used to match a trie to an input sequence.
+// A contraction may match a non-contiguous sequence of bytes in an input string.
+// For example, if there is a contraction for <a, combining_ring>, it should match
+// the sequence <a, combining_cedilla, combining_ring>, as combining_cedilla does
+// not block combining_ring.
+// ctScanner does not automatically skip over non-blocking non-starters, but rather
+// retains the state of the last match and leaves it up to the user to continue
+// the match at the appropriate points.
+type ctScanner struct {
+	states ContractTrieSet
+	s      []byte
+	n      int
+	index  int
+	pindex int
+	done   bool
+}
+
+type ctScannerString struct {
+	states ContractTrieSet
+	s      string
+	n      int
+	index  int
+	pindex int
+	done   bool
+}
+
+func (t ContractTrieSet) scanner(index, n int, b []byte) ctScanner {
+	return ctScanner{s: b, states: t[index:], n: n}
+}
+
+func (t ContractTrieSet) scannerString(index, n int, str string) ctScannerString {
+	return ctScannerString{s: str, states: t[index:], n: n}
+}
+
+// result returns the offset i and bytes consumed p so far.  If no suffix
+// matched, i and p will be 0.
+func (s *ctScanner) result() (i, p int) {
+	return s.index, s.pindex
+}
+
+func (s *ctScannerString) result() (i, p int) {
+	return s.index, s.pindex
+}
+
+const (
+	final   = 0
+	noIndex = 0xFF
+)
+
+// scan matches the longest suffix at the current location in the input
+// and returns the number of bytes consumed.
+func (s *ctScanner) scan(p int) int {
+	pr := p // the p at the rune start
+	str := s.s
+	states, n := s.states, s.n
+	for i := 0; i < n && p < len(str); {
+		e := states[i]
+		c := str[p]
+		// TODO: a significant number of contractions are of a form that
+		// cannot match discontiguous UTF-8 in a normalized string. We could let
+		// a negative value of e.n mean that we can set s.done = true and avoid
+		// the need for additional matches.
+		if c >= e.L {
+			if e.L == c {
+				p++
+				if e.I != noIndex {
+					s.index = int(e.I)
+					s.pindex = p
+				}
+				if e.N != final {
+					i, states, n = 0, states[int(e.H)+n:], int(e.N)
+					if p >= len(str) || utf8.RuneStart(str[p]) {
+						s.states, s.n, pr = states, n, p
+					}
+				} else {
+					s.done = true
+					return p
+				}
+				continue
+			} else if e.N == final && c <= e.H {
+				p++
+				s.done = true
+				s.index = int(c-e.L) + int(e.I)
+				s.pindex = p
+				return p
+			}
+		}
+		i++
+	}
+	return pr
+}
+
+// scan is a verbatim copy of ctScanner.scan.
+func (s *ctScannerString) scan(p int) int {
+	pr := p // the p at the rune start
+	str := s.s
+	states, n := s.states, s.n
+	for i := 0; i < n && p < len(str); {
+		e := states[i]
+		c := str[p]
+		// TODO: a significant number of contractions are of a form that
+		// cannot match discontiguous UTF-8 in a normalized string. We could let
+		// a negative value of e.n mean that we can set s.done = true and avoid
+		// the need for additional matches.
+		if c >= e.L {
+			if e.L == c {
+				p++
+				if e.I != noIndex {
+					s.index = int(e.I)
+					s.pindex = p
+				}
+				if e.N != final {
+					i, states, n = 0, states[int(e.H)+n:], int(e.N)
+					if p >= len(str) || utf8.RuneStart(str[p]) {
+						s.states, s.n, pr = states, n, p
+					}
+				} else {
+					s.done = true
+					return p
+				}
+				continue
+			} else if e.N == final && c <= e.H {
+				p++
+				s.done = true
+				s.index = int(c-e.L) + int(e.I)
+				s.pindex = p
+				return p
+			}
+		}
+		i++
+	}
+	return pr
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/iter.go b/vendor/golang.org/x/text/internal/colltab/iter.go
new file mode 100644
index 0000000..c1b1ba8
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/iter.go
@@ -0,0 +1,178 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package colltab
+
+// An Iter incrementally converts chunks of the input text to collation
+// elements, while ensuring that the collation elements are in normalized order
+// (that is, they are in the order as if the input text were normalized first).
+type Iter struct {
+	Weighter Weighter
+	Elems    []Elem
+	// N is the number of elements in Elems that will not be reordered on
+	// subsequent iterations, N <= len(Elems).
+	N int
+
+	bytes []byte
+	str   string
+	// Because the Elems buffer may contain collation elements that are needed
+	// for look-ahead, we need two positions in the text (bytes or str): one for
+	// the end position in the text for the current iteration and one for the
+	// start of the next call to appendNext.
+	pEnd  int // end position in text corresponding to N.
+	pNext int // pEnd <= pNext.
+}
+
+// Reset sets the position in the current input text to p and discards any
+// results obtained so far.
+func (i *Iter) Reset(p int) {
+	i.Elems = i.Elems[:0]
+	i.N = 0
+	i.pEnd = p
+	i.pNext = p
+}
+
+// Len returns the length of the input text.
+func (i *Iter) Len() int {
+	if i.bytes != nil {
+		return len(i.bytes)
+	}
+	return len(i.str)
+}
+
+// Discard removes the collation elements up to N.
+func (i *Iter) Discard() {
+	// TODO: change this such that only modifiers following starters will have
+	// to be copied.
+	i.Elems = i.Elems[:copy(i.Elems, i.Elems[i.N:])]
+	i.N = 0
+}
+
+// End returns the end position of the input text for which Next has returned
+// results.
+func (i *Iter) End() int {
+	return i.pEnd
+}
+
+// SetInput resets i to input s.
+func (i *Iter) SetInput(s []byte) {
+	i.bytes = s
+	i.str = ""
+	i.Reset(0)
+}
+
+// SetInputString resets i to input s.
+func (i *Iter) SetInputString(s string) {
+	i.str = s
+	i.bytes = nil
+	i.Reset(0)
+}
+
+func (i *Iter) done() bool {
+	return i.pNext >= len(i.str) && i.pNext >= len(i.bytes)
+}
+
+func (i *Iter) appendNext() bool {
+	if i.done() {
+		return false
+	}
+	var sz int
+	if i.bytes == nil {
+		i.Elems, sz = i.Weighter.AppendNextString(i.Elems, i.str[i.pNext:])
+	} else {
+		i.Elems, sz = i.Weighter.AppendNext(i.Elems, i.bytes[i.pNext:])
+	}
+	if sz == 0 {
+		sz = 1
+	}
+	i.pNext += sz
+	return true
+}
+
+// Next appends Elems to the internal array. On each iteration, it will either
+// add starters or modifiers. In the majority of cases, an Elem with a primary
+// value > 0 will have a CCC of 0. The CCC values of collation elements are also
+// used to detect if the input string was not normalized and to adjust the
+// result accordingly.
+func (i *Iter) Next() bool {
+	if i.N == len(i.Elems) && !i.appendNext() {
+		return false
+	}
+
+	// Check if the current segment starts with a starter.
+	prevCCC := i.Elems[len(i.Elems)-1].CCC()
+	if prevCCC == 0 {
+		i.N = len(i.Elems)
+		i.pEnd = i.pNext
+		return true
+	} else if i.Elems[i.N].CCC() == 0 {
+		// set i.N to only cover part of i.Elems for which prevCCC == 0 and
+		// use rest for the next call to next.
+		for i.N++; i.N < len(i.Elems) && i.Elems[i.N].CCC() == 0; i.N++ {
+		}
+		i.pEnd = i.pNext
+		return true
+	}
+
+	// The current (partial) segment starts with modifiers. We need to collect
+	// all successive modifiers to ensure that they are normalized.
+	for {
+		p := len(i.Elems)
+		i.pEnd = i.pNext
+		if !i.appendNext() {
+			break
+		}
+
+		if ccc := i.Elems[p].CCC(); ccc == 0 || len(i.Elems)-i.N > maxCombiningCharacters {
+			// Leave the starter for the next iteration. This ensures that we
+			// do not return sequences of collation elements that cross two
+			// segments.
+			//
+			// TODO: handle large number of combining characters by fully
+			// normalizing the input segment before iteration. This ensures
+			// results are consistent across the text repo.
+			i.N = p
+			return true
+		} else if ccc < prevCCC {
+			i.doNorm(p, ccc) // should be rare, never occurs for NFD and FCC.
+		} else {
+			prevCCC = ccc
+		}
+	}
+
+	done := len(i.Elems) != i.N
+	i.N = len(i.Elems)
+	return done
+}
+
+// nextNoNorm is the same as next, but does not "normalize" the collation
+// elements.
+func (i *Iter) nextNoNorm() bool {
+	// TODO: remove this function. Using this instead of next does not seem
+	// to improve performance in any significant way. We retain this until
+	// later for evaluation purposes.
+	if i.done() {
+		return false
+	}
+	i.appendNext()
+	i.N = len(i.Elems)
+	return true
+}
+
+const maxCombiningCharacters = 30
+
+// doNorm reorders the collation elements in i.Elems.
+// It assumes that blocks of collation elements added with appendNext
+// either start and end with the same CCC or start with CCC == 0.
+// This allows for a single insertion point for the entire block.
+// The correctness of this assumption is verified in builder.go.
+func (i *Iter) doNorm(p int, ccc uint8) {
+	n := len(i.Elems)
+	k := p
+	for p--; p > i.N && ccc < i.Elems[p-1].CCC(); p-- {
+	}
+	i.Elems = append(i.Elems, i.Elems[p:k]...)
+	copy(i.Elems[p:], i.Elems[k:])
+	i.Elems = i.Elems[:n]
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/numeric.go b/vendor/golang.org/x/text/internal/colltab/numeric.go
new file mode 100644
index 0000000..38c255c
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/numeric.go
@@ -0,0 +1,236 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package colltab
+
+import (
+	"unicode"
+	"unicode/utf8"
+)
+
+// NewNumericWeighter wraps w to replace individual digits to sort based on their
+// numeric value.
+//
+// Weighter w must have a free primary weight after the primary weight for 9.
+// If this is not the case, numeric value will sort at the same primary level
+// as the first primary sorting after 9.
+func NewNumericWeighter(w Weighter) Weighter {
+	getElem := func(s string) Elem {
+		elems, _ := w.AppendNextString(nil, s)
+		return elems[0]
+	}
+	nine := getElem("9")
+
+	// Numbers should order before zero, but the DUCET has no room for this.
+	// TODO: move before zero once we use fractional collation elements.
+	ns, _ := MakeElem(nine.Primary()+1, nine.Secondary(), int(nine.Tertiary()), 0)
+
+	return &numericWeighter{
+		Weighter: w,
+
+		// We assume that w sorts digits of different kinds in order of numeric
+		// value and that the tertiary weight order is preserved.
+		//
+		// TODO: evaluate whether it is worth basing the ranges on the Elem
+		// encoding itself once the move to fractional weights is complete.
+		zero:          getElem("0"),
+		zeroSpecialLo: getElem("０"), // U+FF10 FULLWIDTH DIGIT ZERO
+		zeroSpecialHi: getElem("₀"), // U+2080 SUBSCRIPT ZERO
+		nine:          nine,
+		nineSpecialHi: getElem("₉"), // U+2089 SUBSCRIPT NINE
+		numberStart:   ns,
+	}
+}
+
+// A numericWeighter translates a stream of digits into a stream of weights
+// representing the numeric value.
+type numericWeighter struct {
+	Weighter
+
+	// The Elems below all demarcate boundaries of specific ranges. With the
+	// current element encoding digits are in two ranges: normal (default
+	// tertiary value) and special. For most languages, digits have collation
+	// elements in the normal range.
+	//
+	// Note: the range tests are very specific for the element encoding used by
+	// this implementation. The tests in collate_test.go are designed to fail
+	// if this code is not updated when an encoding has changed.
+
+	zero          Elem // normal digit zero
+	zeroSpecialLo Elem // special digit zero, low tertiary value
+	zeroSpecialHi Elem // special digit zero, high tertiary value
+	nine          Elem // normal digit nine
+	nineSpecialHi Elem // special digit nine
+	numberStart   Elem
+}
+
+// AppendNext calls the namesake of the underlying weigher, but replaces single
+// digits with weights representing their value.
+func (nw *numericWeighter) AppendNext(buf []Elem, s []byte) (ce []Elem, n int) {
+	ce, n = nw.Weighter.AppendNext(buf, s)
+	nc := numberConverter{
+		elems: buf,
+		w:     nw,
+		b:     s,
+	}
+	isZero, ok := nc.checkNextDigit(ce)
+	if !ok {
+		return ce, n
+	}
+	// ce might have been grown already, so take it instead of buf.
+	nc.init(ce, len(buf), isZero)
+	for n < len(s) {
+		ce, sz := nw.Weighter.AppendNext(nc.elems, s[n:])
+		nc.b = s
+		n += sz
+		if !nc.update(ce) {
+			break
+		}
+	}
+	return nc.result(), n
+}
+
+// AppendNextString calls the namesake of the underlying weigher, but replaces
+// single digits with weights representing their value.
+func (nw *numericWeighter) AppendNextString(buf []Elem, s string) (ce []Elem, n int) {
+	ce, n = nw.Weighter.AppendNextString(buf, s)
+	nc := numberConverter{
+		elems: buf,
+		w:     nw,
+		s:     s,
+	}
+	isZero, ok := nc.checkNextDigit(ce)
+	if !ok {
+		return ce, n
+	}
+	nc.init(ce, len(buf), isZero)
+	for n < len(s) {
+		ce, sz := nw.Weighter.AppendNextString(nc.elems, s[n:])
+		nc.s = s
+		n += sz
+		if !nc.update(ce) {
+			break
+		}
+	}
+	return nc.result(), n
+}
+
+type numberConverter struct {
+	w *numericWeighter
+
+	elems    []Elem
+	nDigits  int
+	lenIndex int
+
+	s string // set if the input was of type string
+	b []byte // set if the input was of type []byte
+}
+
+// init completes initialization of a numberConverter and prepares it for adding
+// more digits. elems is assumed to have a digit starting at oldLen.
+func (nc *numberConverter) init(elems []Elem, oldLen int, isZero bool) {
+	// Insert a marker indicating the start of a number and and a placeholder
+	// for the number of digits.
+	if isZero {
+		elems = append(elems[:oldLen], nc.w.numberStart, 0)
+	} else {
+		elems = append(elems, 0, 0)
+		copy(elems[oldLen+2:], elems[oldLen:])
+		elems[oldLen] = nc.w.numberStart
+		elems[oldLen+1] = 0
+
+		nc.nDigits = 1
+	}
+	nc.elems = elems
+	nc.lenIndex = oldLen + 1
+}
+
+// checkNextDigit reports whether bufNew adds a single digit relative to the old
+// buffer. If it does, it also reports whether this digit is zero.
+func (nc *numberConverter) checkNextDigit(bufNew []Elem) (isZero, ok bool) {
+	if len(nc.elems) >= len(bufNew) {
+		return false, false
+	}
+	e := bufNew[len(nc.elems)]
+	if e < nc.w.zeroSpecialLo || nc.w.nine < e {
+		// Not a number.
+		return false, false
+	}
+	if e < nc.w.zero {
+		if e > nc.w.nineSpecialHi {
+			// Not a number.
+			return false, false
+		}
+		if !nc.isDigit() {
+			return false, false
+		}
+		isZero = e <= nc.w.zeroSpecialHi
+	} else {
+		// This is the common case if we encounter a digit.
+		isZero = e == nc.w.zero
+	}
+	// Test the remaining added collation elements have a zero primary value.
+	if n := len(bufNew) - len(nc.elems); n > 1 {
+		for i := len(nc.elems) + 1; i < len(bufNew); i++ {
+			if bufNew[i].Primary() != 0 {
+				return false, false
+			}
+		}
+		// In some rare cases, collation elements will encode runes in
+		// unicode.No as a digit. For example Ethiopic digits (U+1369 - U+1371)
+		// are not in Nd. Also some digits that clearly belong in unicode.No,
+		// like U+0C78 TELUGU FRACTION DIGIT ZERO FOR ODD POWERS OF FOUR, have
+		// collation elements indistinguishable from normal digits.
+		// Unfortunately, this means we need to make this check for nearly all
+		// non-Latin digits.
+		//
+		// TODO: check the performance impact and find something better if it is
+		// an issue.
+		if !nc.isDigit() {
+			return false, false
+		}
+	}
+	return isZero, true
+}
+
+func (nc *numberConverter) isDigit() bool {
+	if nc.b != nil {
+		r, _ := utf8.DecodeRune(nc.b)
+		return unicode.In(r, unicode.Nd)
+	}
+	r, _ := utf8.DecodeRuneInString(nc.s)
+	return unicode.In(r, unicode.Nd)
+}
+
+// We currently support a maximum of about 2M digits (the number of primary
+// values). Such numbers will compare correctly against small numbers, but their
+// comparison against other large numbers is undefined.
+//
+// TODO: define a proper fallback, such as comparing large numbers textually or
+// actually allowing numbers of unlimited length.
+//
+// TODO: cap this to a lower number (like 100) and maybe allow a larger number
+// in an option?
+const maxDigits = 1<<maxPrimaryBits - 1
+
+func (nc *numberConverter) update(elems []Elem) bool {
+	isZero, ok := nc.checkNextDigit(elems)
+	if nc.nDigits == 0 && isZero {
+		return true
+	}
+	nc.elems = elems
+	if !ok {
+		return false
+	}
+	nc.nDigits++
+	return nc.nDigits < maxDigits
+}
+
+// result fills in the length element for the digit sequence and returns the
+// completed collation elements.
+func (nc *numberConverter) result() []Elem {
+	e, _ := MakeElem(nc.nDigits, defaultSecondary, defaultTertiary, 0)
+	nc.elems[nc.lenIndex] = e
+	return nc.elems
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/table.go b/vendor/golang.org/x/text/internal/colltab/table.go
new file mode 100644
index 0000000..e26e36d
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/table.go
@@ -0,0 +1,275 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package colltab
+
+import (
+	"unicode/utf8"
+
+	"golang.org/x/text/unicode/norm"
+)
+
+// Table holds all collation data for a given collation ordering.
+type Table struct {
+	Index Trie // main trie
+
+	// expansion info
+	ExpandElem []uint32
+
+	// contraction info
+	ContractTries  ContractTrieSet
+	ContractElem   []uint32
+	MaxContractLen int
+	VariableTop    uint32
+}
+
+func (t *Table) AppendNext(w []Elem, b []byte) (res []Elem, n int) {
+	return t.appendNext(w, source{bytes: b})
+}
+
+func (t *Table) AppendNextString(w []Elem, s string) (res []Elem, n int) {
+	return t.appendNext(w, source{str: s})
+}
+
+func (t *Table) Start(p int, b []byte) int {
+	// TODO: implement
+	panic("not implemented")
+}
+
+func (t *Table) StartString(p int, s string) int {
+	// TODO: implement
+	panic("not implemented")
+}
+
+func (t *Table) Domain() []string {
+	// TODO: implement
+	panic("not implemented")
+}
+
+func (t *Table) Top() uint32 {
+	return t.VariableTop
+}
+
+type source struct {
+	str   string
+	bytes []byte
+}
+
+func (src *source) lookup(t *Table) (ce Elem, sz int) {
+	if src.bytes == nil {
+		return t.Index.lookupString(src.str)
+	}
+	return t.Index.lookup(src.bytes)
+}
+
+func (src *source) tail(sz int) {
+	if src.bytes == nil {
+		src.str = src.str[sz:]
+	} else {
+		src.bytes = src.bytes[sz:]
+	}
+}
+
+func (src *source) nfd(buf []byte, end int) []byte {
+	if src.bytes == nil {
+		return norm.NFD.AppendString(buf[:0], src.str[:end])
+	}
+	return norm.NFD.Append(buf[:0], src.bytes[:end]...)
+}
+
+func (src *source) rune() (r rune, sz int) {
+	if src.bytes == nil {
+		return utf8.DecodeRuneInString(src.str)
+	}
+	return utf8.DecodeRune(src.bytes)
+}
+
+func (src *source) properties(f norm.Form) norm.Properties {
+	if src.bytes == nil {
+		return f.PropertiesString(src.str)
+	}
+	return f.Properties(src.bytes)
+}
+
+// appendNext appends the weights corresponding to the next rune or
+// contraction in s.  If a contraction is matched to a discontinuous
+// sequence of runes, the weights for the interstitial runes are
+// appended as well.  It returns a new slice that includes the appended
+// weights and the number of bytes consumed from s.
+func (t *Table) appendNext(w []Elem, src source) (res []Elem, n int) {
+	ce, sz := src.lookup(t)
+	tp := ce.ctype()
+	if tp == ceNormal {
+		if ce == 0 {
+			r, _ := src.rune()
+			const (
+				hangulSize  = 3
+				firstHangul = 0xAC00
+				lastHangul  = 0xD7A3
+			)
+			if r >= firstHangul && r <= lastHangul {
+				// TODO: performance can be considerably improved here.
+				n = sz
+				var buf [16]byte // Used for decomposing Hangul.
+				for b := src.nfd(buf[:0], hangulSize); len(b) > 0; b = b[sz:] {
+					ce, sz = t.Index.lookup(b)
+					w = append(w, ce)
+				}
+				return w, n
+			}
+			ce = makeImplicitCE(implicitPrimary(r))
+		}
+		w = append(w, ce)
+	} else if tp == ceExpansionIndex {
+		w = t.appendExpansion(w, ce)
+	} else if tp == ceContractionIndex {
+		n := 0
+		src.tail(sz)
+		if src.bytes == nil {
+			w, n = t.matchContractionString(w, ce, src.str)
+		} else {
+			w, n = t.matchContraction(w, ce, src.bytes)
+		}
+		sz += n
+	} else if tp == ceDecompose {
+		// Decompose using NFKD and replace tertiary weights.
+		t1, t2 := splitDecompose(ce)
+		i := len(w)
+		nfkd := src.properties(norm.NFKD).Decomposition()
+		for p := 0; len(nfkd) > 0; nfkd = nfkd[p:] {
+			w, p = t.appendNext(w, source{bytes: nfkd})
+		}
+		w[i] = w[i].updateTertiary(t1)
+		if i++; i < len(w) {
+			w[i] = w[i].updateTertiary(t2)
+			for i++; i < len(w); i++ {
+				w[i] = w[i].updateTertiary(maxTertiary)
+			}
+		}
+	}
+	return w, sz
+}
+
+func (t *Table) appendExpansion(w []Elem, ce Elem) []Elem {
+	i := splitExpandIndex(ce)
+	n := int(t.ExpandElem[i])
+	i++
+	for _, ce := range t.ExpandElem[i : i+n] {
+		w = append(w, Elem(ce))
+	}
+	return w
+}
+
+func (t *Table) matchContraction(w []Elem, ce Elem, suffix []byte) ([]Elem, int) {
+	index, n, offset := splitContractIndex(ce)
+
+	scan := t.ContractTries.scanner(index, n, suffix)
+	buf := [norm.MaxSegmentSize]byte{}
+	bufp := 0
+	p := scan.scan(0)
+
+	if !scan.done && p < len(suffix) && suffix[p] >= utf8.RuneSelf {
+		// By now we should have filtered most cases.
+		p0 := p
+		bufn := 0
+		rune := norm.NFD.Properties(suffix[p:])
+		p += rune.Size()
+		if rune.LeadCCC() != 0 {
+			prevCC := rune.TrailCCC()
+			// A gap may only occur in the last normalization segment.
+			// This also ensures that len(scan.s) < norm.MaxSegmentSize.
+			if end := norm.NFD.FirstBoundary(suffix[p:]); end != -1 {
+				scan.s = suffix[:p+end]
+			}
+			for p < len(suffix) && !scan.done && suffix[p] >= utf8.RuneSelf {
+				rune = norm.NFD.Properties(suffix[p:])
+				if ccc := rune.LeadCCC(); ccc == 0 || prevCC >= ccc {
+					break
+				}
+				prevCC = rune.TrailCCC()
+				if pp := scan.scan(p); pp != p {
+					// Copy the interstitial runes for later processing.
+					bufn += copy(buf[bufn:], suffix[p0:p])
+					if scan.pindex == pp {
+						bufp = bufn
+					}
+					p, p0 = pp, pp
+				} else {
+					p += rune.Size()
+				}
+			}
+		}
+	}
+	// Append weights for the matched contraction, which may be an expansion.
+	i, n := scan.result()
+	ce = Elem(t.ContractElem[i+offset])
+	if ce.ctype() == ceNormal {
+		w = append(w, ce)
+	} else {
+		w = t.appendExpansion(w, ce)
+	}
+	// Append weights for the runes in the segment not part of the contraction.
+	for b, p := buf[:bufp], 0; len(b) > 0; b = b[p:] {
+		w, p = t.appendNext(w, source{bytes: b})
+	}
+	return w, n
+}
+
+// TODO: unify the two implementations. This is best done after first simplifying
+// the algorithm taking into account the inclusion of both NFC and NFD forms
+// in the table.
+func (t *Table) matchContractionString(w []Elem, ce Elem, suffix string) ([]Elem, int) {
+	index, n, offset := splitContractIndex(ce)
+
+	scan := t.ContractTries.scannerString(index, n, suffix)
+	buf := [norm.MaxSegmentSize]byte{}
+	bufp := 0
+	p := scan.scan(0)
+
+	if !scan.done && p < len(suffix) && suffix[p] >= utf8.RuneSelf {
+		// By now we should have filtered most cases.
+		p0 := p
+		bufn := 0
+		rune := norm.NFD.PropertiesString(suffix[p:])
+		p += rune.Size()
+		if rune.LeadCCC() != 0 {
+			prevCC := rune.TrailCCC()
+			// A gap may only occur in the last normalization segment.
+			// This also ensures that len(scan.s) < norm.MaxSegmentSize.
+			if end := norm.NFD.FirstBoundaryInString(suffix[p:]); end != -1 {
+				scan.s = suffix[:p+end]
+			}
+			for p < len(suffix) && !scan.done && suffix[p] >= utf8.RuneSelf {
+				rune = norm.NFD.PropertiesString(suffix[p:])
+				if ccc := rune.LeadCCC(); ccc == 0 || prevCC >= ccc {
+					break
+				}
+				prevCC = rune.TrailCCC()
+				if pp := scan.scan(p); pp != p {
+					// Copy the interstitial runes for later processing.
+					bufn += copy(buf[bufn:], suffix[p0:p])
+					if scan.pindex == pp {
+						bufp = bufn
+					}
+					p, p0 = pp, pp
+				} else {
+					p += rune.Size()
+				}
+			}
+		}
+	}
+	// Append weights for the matched contraction, which may be an expansion.
+	i, n := scan.result()
+	ce = Elem(t.ContractElem[i+offset])
+	if ce.ctype() == ceNormal {
+		w = append(w, ce)
+	} else {
+		w = t.appendExpansion(w, ce)
+	}
+	// Append weights for the runes in the segment not part of the contraction.
+	for b, p := buf[:bufp], 0; len(b) > 0; b = b[p:] {
+		w, p = t.appendNext(w, source{bytes: b})
+	}
+	return w, n
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/trie.go b/vendor/golang.org/x/text/internal/colltab/trie.go
new file mode 100644
index 0000000..a0eaa0d
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/trie.go
@@ -0,0 +1,159 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The trie in this file is used to associate the first full character in an
+// UTF-8 string to a collation element. All but the last byte in a UTF-8 byte
+// sequence are used to lookup offsets in the index table to be used for the
+// next byte. The last byte is used to index into a table of collation elements.
+// For a full description, see go.text/collate/build/trie.go.
+
+package colltab
+
+const blockSize = 64
+
+type Trie struct {
+	Index0  []uint16 // index for first byte (0xC0-0xFF)
+	Values0 []uint32 // index for first byte (0x00-0x7F)
+	Index   []uint16
+	Values  []uint32
+}
+
+const (
+	t1 = 0x00 // 0000 0000
+	tx = 0x80 // 1000 0000
+	t2 = 0xC0 // 1100 0000
+	t3 = 0xE0 // 1110 0000
+	t4 = 0xF0 // 1111 0000
+	t5 = 0xF8 // 1111 1000
+	t6 = 0xFC // 1111 1100
+	te = 0xFE // 1111 1110
+)
+
+func (t *Trie) lookupValue(n uint16, b byte) Elem {
+	return Elem(t.Values[int(n)<<6+int(b)])
+}
+
+// lookup returns the trie value for the first UTF-8 encoding in s and
+// the width in bytes of this encoding. The size will be 0 if s does not
+// hold enough bytes to complete the encoding. len(s) must be greater than 0.
+func (t *Trie) lookup(s []byte) (v Elem, sz int) {
+	c0 := s[0]
+	switch {
+	case c0 < tx:
+		return Elem(t.Values0[c0]), 1
+	case c0 < t2:
+		return 0, 1
+	case c0 < t3:
+		if len(s) < 2 {
+			return 0, 0
+		}
+		i := t.Index0[c0]
+		c1 := s[1]
+		if c1 < tx || t2 <= c1 {
+			return 0, 1
+		}
+		return t.lookupValue(i, c1), 2
+	case c0 < t4:
+		if len(s) < 3 {
+			return 0, 0
+		}
+		i := t.Index0[c0]
+		c1 := s[1]
+		if c1 < tx || t2 <= c1 {
+			return 0, 1
+		}
+		o := int(i)<<6 + int(c1)
+		i = t.Index[o]
+		c2 := s[2]
+		if c2 < tx || t2 <= c2 {
+			return 0, 2
+		}
+		return t.lookupValue(i, c2), 3
+	case c0 < t5:
+		if len(s) < 4 {
+			return 0, 0
+		}
+		i := t.Index0[c0]
+		c1 := s[1]
+		if c1 < tx || t2 <= c1 {
+			return 0, 1
+		}
+		o := int(i)<<6 + int(c1)
+		i = t.Index[o]
+		c2 := s[2]
+		if c2 < tx || t2 <= c2 {
+			return 0, 2
+		}
+		o = int(i)<<6 + int(c2)
+		i = t.Index[o]
+		c3 := s[3]
+		if c3 < tx || t2 <= c3 {
+			return 0, 3
+		}
+		return t.lookupValue(i, c3), 4
+	}
+	// Illegal rune
+	return 0, 1
+}
+
+// The body of lookupString is a verbatim copy of that of lookup.
+func (t *Trie) lookupString(s string) (v Elem, sz int) {
+	c0 := s[0]
+	switch {
+	case c0 < tx:
+		return Elem(t.Values0[c0]), 1
+	case c0 < t2:
+		return 0, 1
+	case c0 < t3:
+		if len(s) < 2 {
+			return 0, 0
+		}
+		i := t.Index0[c0]
+		c1 := s[1]
+		if c1 < tx || t2 <= c1 {
+			return 0, 1
+		}
+		return t.lookupValue(i, c1), 2
+	case c0 < t4:
+		if len(s) < 3 {
+			return 0, 0
+		}
+		i := t.Index0[c0]
+		c1 := s[1]
+		if c1 < tx || t2 <= c1 {
+			return 0, 1
+		}
+		o := int(i)<<6 + int(c1)
+		i = t.Index[o]
+		c2 := s[2]
+		if c2 < tx || t2 <= c2 {
+			return 0, 2
+		}
+		return t.lookupValue(i, c2), 3
+	case c0 < t5:
+		if len(s) < 4 {
+			return 0, 0
+		}
+		i := t.Index0[c0]
+		c1 := s[1]
+		if c1 < tx || t2 <= c1 {
+			return 0, 1
+		}
+		o := int(i)<<6 + int(c1)
+		i = t.Index[o]
+		c2 := s[2]
+		if c2 < tx || t2 <= c2 {
+			return 0, 2
+		}
+		o = int(i)<<6 + int(c2)
+		i = t.Index[o]
+		c3 := s[3]
+		if c3 < tx || t2 <= c3 {
+			return 0, 3
+		}
+		return t.lookupValue(i, c3), 4
+	}
+	// Illegal rune
+	return 0, 1
+}
diff --git a/vendor/golang.org/x/text/internal/colltab/weighter.go b/vendor/golang.org/x/text/internal/colltab/weighter.go
new file mode 100644
index 0000000..f1ec45f
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/colltab/weighter.go
@@ -0,0 +1,31 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package colltab // import "golang.org/x/text/internal/colltab"
+
+// A Weighter can be used as a source for Collator and Searcher.
+type Weighter interface {
+	// Start finds the start of the segment that includes position p.
+	Start(p int, b []byte) int
+
+	// StartString finds the start of the segment that includes position p.
+	StartString(p int, s string) int
+
+	// AppendNext appends Elems to buf corresponding to the longest match
+	// of a single character or contraction from the start of s.
+	// It returns the new buf and the number of bytes consumed.
+	AppendNext(buf []Elem, s []byte) (ce []Elem, n int)
+
+	// AppendNextString appends Elems to buf corresponding to the longest match
+	// of a single character or contraction from the start of s.
+	// It returns the new buf and the number of bytes consumed.
+	AppendNextString(buf []Elem, s string) (ce []Elem, n int)
+
+	// Domain returns a slice of all single characters and contractions for which
+	// collation elements are defined in this table.
+	Domain() []string
+
+	// Top returns the highest variable primary value.
+	Top() uint32
+}
diff --git a/vendor/golang.org/x/text/internal/gen/code.go b/vendor/golang.org/x/text/internal/gen/code.go
new file mode 100644
index 0000000..0389509
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/gen/code.go
@@ -0,0 +1,369 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gen
+
+import (
+	"bytes"
+	"encoding/gob"
+	"fmt"
+	"hash"
+	"hash/fnv"
+	"io"
+	"log"
+	"os"
+	"reflect"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// This file contains utilities for generating code.
+
+// TODO: other write methods like:
+// - slices, maps, types, etc.
+
+// CodeWriter is a utility for writing structured code. It computes the content
+// hash and size of written content. It ensures there are newlines between
+// written code blocks.
+type CodeWriter struct {
+	buf  bytes.Buffer
+	Size int
+	Hash hash.Hash32 // content hash
+	gob  *gob.Encoder
+	// For comments we skip the usual one-line separator if they are followed by
+	// a code block.
+	skipSep bool
+}
+
+func (w *CodeWriter) Write(p []byte) (n int, err error) {
+	return w.buf.Write(p)
+}
+
+// NewCodeWriter returns a new CodeWriter.
+func NewCodeWriter() *CodeWriter {
+	h := fnv.New32()
+	return &CodeWriter{Hash: h, gob: gob.NewEncoder(h)}
+}
+
+// WriteGoFile appends the buffer with the total size of all created structures
+// and writes it as a Go file to the the given file with the given package name.
+func (w *CodeWriter) WriteGoFile(filename, pkg string) {
+	f, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer f.Close()
+	if _, err = w.WriteGo(f, pkg, ""); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+// WriteVersionedGoFile appends the buffer with the total size of all created
+// structures and writes it as a Go file to the the given file with the given
+// package name and build tags for the current Unicode version,
+func (w *CodeWriter) WriteVersionedGoFile(filename, pkg string) {
+	tags := buildTags()
+	if tags != "" {
+		filename = insertVersion(filename, UnicodeVersion())
+	}
+	f, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer f.Close()
+	if _, err = w.WriteGo(f, pkg, tags); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+// WriteGo appends the buffer with the total size of all created structures and
+// writes it as a Go file to the the given writer with the given package name.
+func (w *CodeWriter) WriteGo(out io.Writer, pkg, tags string) (n int, err error) {
+	sz := w.Size
+	w.WriteComment("Total table size %d bytes (%dKiB); checksum: %X\n", sz, sz/1024, w.Hash.Sum32())
+	defer w.buf.Reset()
+	return WriteGo(out, pkg, tags, w.buf.Bytes())
+}
+
+func (w *CodeWriter) printf(f string, x ...interface{}) {
+	fmt.Fprintf(w, f, x...)
+}
+
+func (w *CodeWriter) insertSep() {
+	if w.skipSep {
+		w.skipSep = false
+		return
+	}
+	// Use at least two newlines to ensure a blank space between the previous
+	// block. WriteGoFile will remove extraneous newlines.
+	w.printf("\n\n")
+}
+
+// WriteComment writes a comment block. All line starts are prefixed with "//".
+// Initial empty lines are gobbled. The indentation for the first line is
+// stripped from consecutive lines.
+func (w *CodeWriter) WriteComment(comment string, args ...interface{}) {
+	s := fmt.Sprintf(comment, args...)
+	s = strings.Trim(s, "\n")
+
+	// Use at least two newlines to ensure a blank space between the previous
+	// block. WriteGoFile will remove extraneous newlines.
+	w.printf("\n\n// ")
+	w.skipSep = true
+
+	// strip first indent level.
+	sep := "\n"
+	for ; len(s) > 0 && (s[0] == '\t' || s[0] == ' '); s = s[1:] {
+		sep += s[:1]
+	}
+
+	strings.NewReplacer(sep, "\n// ", "\n", "\n// ").WriteString(w, s)
+
+	w.printf("\n")
+}
+
+func (w *CodeWriter) writeSizeInfo(size int) {
+	w.printf("// Size: %d bytes\n", size)
+}
+
+// WriteConst writes a constant of the given name and value.
+func (w *CodeWriter) WriteConst(name string, x interface{}) {
+	w.insertSep()
+	v := reflect.ValueOf(x)
+
+	switch v.Type().Kind() {
+	case reflect.String:
+		w.printf("const %s %s = ", name, typeName(x))
+		w.WriteString(v.String())
+		w.printf("\n")
+	default:
+		w.printf("const %s = %#v\n", name, x)
+	}
+}
+
+// WriteVar writes a variable of the given name and value.
+func (w *CodeWriter) WriteVar(name string, x interface{}) {
+	w.insertSep()
+	v := reflect.ValueOf(x)
+	oldSize := w.Size
+	sz := int(v.Type().Size())
+	w.Size += sz
+
+	switch v.Type().Kind() {
+	case reflect.String:
+		w.printf("var %s %s = ", name, typeName(x))
+		w.WriteString(v.String())
+	case reflect.Struct:
+		w.gob.Encode(x)
+		fallthrough
+	case reflect.Slice, reflect.Array:
+		w.printf("var %s = ", name)
+		w.writeValue(v)
+		w.writeSizeInfo(w.Size - oldSize)
+	default:
+		w.printf("var %s %s = ", name, typeName(x))
+		w.gob.Encode(x)
+		w.writeValue(v)
+		w.writeSizeInfo(w.Size - oldSize)
+	}
+	w.printf("\n")
+}
+
+func (w *CodeWriter) writeValue(v reflect.Value) {
+	x := v.Interface()
+	switch v.Kind() {
+	case reflect.String:
+		w.WriteString(v.String())
+	case reflect.Array:
+		// Don't double count: callers of WriteArray count on the size being
+		// added, so we need to discount it here.
+		w.Size -= int(v.Type().Size())
+		w.writeSlice(x, true)
+	case reflect.Slice:
+		w.writeSlice(x, false)
+	case reflect.Struct:
+		w.printf("%s{\n", typeName(v.Interface()))
+		t := v.Type()
+		for i := 0; i < v.NumField(); i++ {
+			w.printf("%s: ", t.Field(i).Name)
+			w.writeValue(v.Field(i))
+			w.printf(",\n")
+		}
+		w.printf("}")
+	default:
+		w.printf("%#v", x)
+	}
+}
+
+// WriteString writes a string literal.
+func (w *CodeWriter) WriteString(s string) {
+	s = strings.Replace(s, `\`, `\\`, -1)
+	io.WriteString(w.Hash, s) // content hash
+	w.Size += len(s)
+
+	const maxInline = 40
+	if len(s) <= maxInline {
+		w.printf("%q", s)
+		return
+	}
+
+	// We will render the string as a multi-line string.
+	const maxWidth = 80 - 4 - len(`"`) - len(`" +`)
+
+	// When starting on its own line, go fmt indents line 2+ an extra level.
+	n, max := maxWidth, maxWidth-4
+
+	// As per https://golang.org/issue/18078, the compiler has trouble
+	// compiling the concatenation of many strings, s0 + s1 + s2 + ... + sN,
+	// for large N. We insert redundant, explicit parentheses to work around
+	// that, lowering the N at any given step: (s0 + s1 + ... + s63) + (s64 +
+	// ... + s127) + etc + (etc + ... + sN).
+	explicitParens, extraComment := len(s) > 128*1024, ""
+	if explicitParens {
+		w.printf(`(`)
+		extraComment = "; the redundant, explicit parens are for https://golang.org/issue/18078"
+	}
+
+	// Print "" +\n, if a string does not start on its own line.
+	b := w.buf.Bytes()
+	if p := len(bytes.TrimRight(b, " \t")); p > 0 && b[p-1] != '\n' {
+		w.printf("\"\" + // Size: %d bytes%s\n", len(s), extraComment)
+		n, max = maxWidth, maxWidth
+	}
+
+	w.printf(`"`)
+
+	for sz, p, nLines := 0, 0, 0; p < len(s); {
+		var r rune
+		r, sz = utf8.DecodeRuneInString(s[p:])
+		out := s[p : p+sz]
+		chars := 1
+		if !unicode.IsPrint(r) || r == utf8.RuneError || r == '"' {
+			switch sz {
+			case 1:
+				out = fmt.Sprintf("\\x%02x", s[p])
+			case 2, 3:
+				out = fmt.Sprintf("\\u%04x", r)
+			case 4:
+				out = fmt.Sprintf("\\U%08x", r)
+			}
+			chars = len(out)
+		}
+		if n -= chars; n < 0 {
+			nLines++
+			if explicitParens && nLines&63 == 63 {
+				w.printf("\") + (\"")
+			}
+			w.printf("\" +\n\"")
+			n = max - len(out)
+		}
+		w.printf("%s", out)
+		p += sz
+	}
+	w.printf(`"`)
+	if explicitParens {
+		w.printf(`)`)
+	}
+}
+
+// WriteSlice writes a slice value.
+func (w *CodeWriter) WriteSlice(x interface{}) {
+	w.writeSlice(x, false)
+}
+
+// WriteArray writes an array value.
+func (w *CodeWriter) WriteArray(x interface{}) {
+	w.writeSlice(x, true)
+}
+
+func (w *CodeWriter) writeSlice(x interface{}, isArray bool) {
+	v := reflect.ValueOf(x)
+	w.gob.Encode(v.Len())
+	w.Size += v.Len() * int(v.Type().Elem().Size())
+	name := typeName(x)
+	if isArray {
+		name = fmt.Sprintf("[%d]%s", v.Len(), name[strings.Index(name, "]")+1:])
+	}
+	if isArray {
+		w.printf("%s{\n", name)
+	} else {
+		w.printf("%s{ // %d elements\n", name, v.Len())
+	}
+
+	switch kind := v.Type().Elem().Kind(); kind {
+	case reflect.String:
+		for _, s := range x.([]string) {
+			w.WriteString(s)
+			w.printf(",\n")
+		}
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		// nLine and nBlock are the number of elements per line and block.
+		nLine, nBlock, format := 8, 64, "%d,"
+		switch kind {
+		case reflect.Uint8:
+			format = "%#02x,"
+		case reflect.Uint16:
+			format = "%#04x,"
+		case reflect.Uint32:
+			nLine, nBlock, format = 4, 32, "%#08x,"
+		case reflect.Uint, reflect.Uint64:
+			nLine, nBlock, format = 4, 32, "%#016x,"
+		case reflect.Int8:
+			nLine = 16
+		}
+		n := nLine
+		for i := 0; i < v.Len(); i++ {
+			if i%nBlock == 0 && v.Len() > nBlock {
+				w.printf("// Entry %X - %X\n", i, i+nBlock-1)
+			}
+			x := v.Index(i).Interface()
+			w.gob.Encode(x)
+			w.printf(format, x)
+			if n--; n == 0 {
+				n = nLine
+				w.printf("\n")
+			}
+		}
+		w.printf("\n")
+	case reflect.Struct:
+		zero := reflect.Zero(v.Type().Elem()).Interface()
+		for i := 0; i < v.Len(); i++ {
+			x := v.Index(i).Interface()
+			w.gob.EncodeValue(v)
+			if !reflect.DeepEqual(zero, x) {
+				line := fmt.Sprintf("%#v,\n", x)
+				line = line[strings.IndexByte(line, '{'):]
+				w.printf("%d: ", i)
+				w.printf(line)
+			}
+		}
+	case reflect.Array:
+		for i := 0; i < v.Len(); i++ {
+			w.printf("%d: %#v,\n", i, v.Index(i).Interface())
+		}
+	default:
+		panic("gen: slice elem type not supported")
+	}
+	w.printf("}")
+}
+
+// WriteType writes a definition of the type of the given value and returns the
+// type name.
+func (w *CodeWriter) WriteType(x interface{}) string {
+	t := reflect.TypeOf(x)
+	w.printf("type %s struct {\n", t.Name())
+	for i := 0; i < t.NumField(); i++ {
+		w.printf("\t%s %s\n", t.Field(i).Name, t.Field(i).Type)
+	}
+	w.printf("}\n")
+	return t.Name()
+}
+
+// typeName returns the name of the go type of x.
+func typeName(x interface{}) string {
+	t := reflect.ValueOf(x).Type()
+	return strings.Replace(fmt.Sprint(t), "main.", "", 1)
+}
diff --git a/vendor/golang.org/x/text/internal/gen/gen.go b/vendor/golang.org/x/text/internal/gen/gen.go
new file mode 100644
index 0000000..4c3f760
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/gen/gen.go
@@ -0,0 +1,333 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package gen contains common code for the various code generation tools in the
+// text repository. Its usage ensures consistency between tools.
+//
+// This package defines command line flags that are common to most generation
+// tools. The flags allow for specifying specific Unicode and CLDR versions
+// in the public Unicode data repository (http://www.unicode.org/Public).
+//
+// A local Unicode data mirror can be set through the flag -local or the
+// environment variable UNICODE_DIR. The former takes precedence. The local
+// directory should follow the same structure as the public repository.
+//
+// IANA data can also optionally be mirrored by putting it in the iana directory
+// rooted at the top of the local mirror. Beware, though, that IANA data is not
+// versioned. So it is up to the developer to use the right version.
+package gen // import "golang.org/x/text/internal/gen"
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/build"
+	"go/format"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"sync"
+	"unicode"
+
+	"golang.org/x/text/unicode/cldr"
+)
+
+var (
+	url = flag.String("url",
+		"http://www.unicode.org/Public",
+		"URL of Unicode database directory")
+	iana = flag.String("iana",
+		"http://www.iana.org",
+		"URL of the IANA repository")
+	unicodeVersion = flag.String("unicode",
+		getEnv("UNICODE_VERSION", unicode.Version),
+		"unicode version to use")
+	cldrVersion = flag.String("cldr",
+		getEnv("CLDR_VERSION", cldr.Version),
+		"cldr version to use")
+)
+
+func getEnv(name, def string) string {
+	if v := os.Getenv(name); v != "" {
+		return v
+	}
+	return def
+}
+
+// Init performs common initialization for a gen command. It parses the flags
+// and sets up the standard logging parameters.
+func Init() {
+	log.SetPrefix("")
+	log.SetFlags(log.Lshortfile)
+	flag.Parse()
+}
+
+const header = `// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+`
+
+// UnicodeVersion reports the requested Unicode version.
+func UnicodeVersion() string {
+	return *unicodeVersion
+}
+
+// CLDRVersion reports the requested CLDR version.
+func CLDRVersion() string {
+	return *cldrVersion
+}
+
+var tags = []struct{ version, buildTags string }{
+	{"10.0.0", "go1.10"},
+	{"", "!go1.10"},
+}
+
+// buildTags reports the build tags used for the current Unicode version.
+func buildTags() string {
+	v := UnicodeVersion()
+	for _, x := range tags {
+		// We should do a numeric comparison, but including the collate package
+		// would create an import cycle. We approximate it by assuming that
+		// longer version strings are later.
+		if len(x.version) <= len(v) {
+			return x.buildTags
+		}
+		if len(x.version) == len(v) && x.version <= v {
+			return x.buildTags
+		}
+	}
+	return tags[0].buildTags
+}
+
+// IsLocal reports whether data files are available locally.
+func IsLocal() bool {
+	dir, err := localReadmeFile()
+	if err != nil {
+		return false
+	}
+	if _, err = os.Stat(dir); err != nil {
+		return false
+	}
+	return true
+}
+
+// OpenUCDFile opens the requested UCD file. The file is specified relative to
+// the public Unicode root directory. It will call log.Fatal if there are any
+// errors.
+func OpenUCDFile(file string) io.ReadCloser {
+	return openUnicode(path.Join(*unicodeVersion, "ucd", file))
+}
+
+// OpenCLDRCoreZip opens the CLDR core zip file. It will call log.Fatal if there
+// are any errors.
+func OpenCLDRCoreZip() io.ReadCloser {
+	return OpenUnicodeFile("cldr", *cldrVersion, "core.zip")
+}
+
+// OpenUnicodeFile opens the requested file of the requested category from the
+// root of the Unicode data archive. The file is specified relative to the
+// public Unicode root directory. If version is "", it will use the default
+// Unicode version. It will call log.Fatal if there are any errors.
+func OpenUnicodeFile(category, version, file string) io.ReadCloser {
+	if version == "" {
+		version = UnicodeVersion()
+	}
+	return openUnicode(path.Join(category, version, file))
+}
+
+// OpenIANAFile opens the requested IANA file. The file is specified relative
+// to the IANA root, which is typically either http://www.iana.org or the
+// iana directory in the local mirror. It will call log.Fatal if there are any
+// errors.
+func OpenIANAFile(path string) io.ReadCloser {
+	return Open(*iana, "iana", path)
+}
+
+var (
+	dirMutex sync.Mutex
+	localDir string
+)
+
+const permissions = 0755
+
+func localReadmeFile() (string, error) {
+	p, err := build.Import("golang.org/x/text", "", build.FindOnly)
+	if err != nil {
+		return "", fmt.Errorf("Could not locate package: %v", err)
+	}
+	return filepath.Join(p.Dir, "DATA", "README"), nil
+}
+
+func getLocalDir() string {
+	dirMutex.Lock()
+	defer dirMutex.Unlock()
+
+	readme, err := localReadmeFile()
+	if err != nil {
+		log.Fatal(err)
+	}
+	dir := filepath.Dir(readme)
+	if _, err := os.Stat(readme); err != nil {
+		if err := os.MkdirAll(dir, permissions); err != nil {
+			log.Fatalf("Could not create directory: %v", err)
+		}
+		ioutil.WriteFile(readme, []byte(readmeTxt), permissions)
+	}
+	return dir
+}
+
+const readmeTxt = `Generated by golang.org/x/text/internal/gen. DO NOT EDIT.
+
+This directory contains downloaded files used to generate the various tables
+in the golang.org/x/text subrepo.
+
+Note that the language subtag repo (iana/assignments/language-subtag-registry)
+and all other times in the iana subdirectory are not versioned and will need
+to be periodically manually updated. The easiest way to do this is to remove
+the entire iana directory. This is mostly of concern when updating the language
+package.
+`
+
+// Open opens subdir/path if a local directory is specified and the file exists,
+// where subdir is a directory relative to the local root, or fetches it from
+// urlRoot/path otherwise. It will call log.Fatal if there are any errors.
+func Open(urlRoot, subdir, path string) io.ReadCloser {
+	file := filepath.Join(getLocalDir(), subdir, filepath.FromSlash(path))
+	return open(file, urlRoot, path)
+}
+
+func openUnicode(path string) io.ReadCloser {
+	file := filepath.Join(getLocalDir(), filepath.FromSlash(path))
+	return open(file, *url, path)
+}
+
+// TODO: automatically periodically update non-versioned files.
+
+func open(file, urlRoot, path string) io.ReadCloser {
+	if f, err := os.Open(file); err == nil {
+		return f
+	}
+	r := get(urlRoot, path)
+	defer r.Close()
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		log.Fatalf("Could not download file: %v", err)
+	}
+	os.MkdirAll(filepath.Dir(file), permissions)
+	if err := ioutil.WriteFile(file, b, permissions); err != nil {
+		log.Fatalf("Could not create file: %v", err)
+	}
+	return ioutil.NopCloser(bytes.NewReader(b))
+}
+
+func get(root, path string) io.ReadCloser {
+	url := root + "/" + path
+	fmt.Printf("Fetching %s...", url)
+	defer fmt.Println(" done.")
+	resp, err := http.Get(url)
+	if err != nil {
+		log.Fatalf("HTTP GET: %v", err)
+	}
+	if resp.StatusCode != 200 {
+		log.Fatalf("Bad GET status for %q: %q", url, resp.Status)
+	}
+	return resp.Body
+}
+
+// TODO: use Write*Version in all applicable packages.
+
+// WriteUnicodeVersion writes a constant for the Unicode version from which the
+// tables are generated.
+func WriteUnicodeVersion(w io.Writer) {
+	fmt.Fprintf(w, "// UnicodeVersion is the Unicode version from which the tables in this package are derived.\n")
+	fmt.Fprintf(w, "const UnicodeVersion = %q\n\n", UnicodeVersion())
+}
+
+// WriteCLDRVersion writes a constant for the CLDR version from which the
+// tables are generated.
+func WriteCLDRVersion(w io.Writer) {
+	fmt.Fprintf(w, "// CLDRVersion is the CLDR version from which the tables in this package are derived.\n")
+	fmt.Fprintf(w, "const CLDRVersion = %q\n\n", CLDRVersion())
+}
+
+// WriteGoFile prepends a standard file comment and package statement to the
+// given bytes, applies gofmt, and writes them to a file with the given name.
+// It will call log.Fatal if there are any errors.
+func WriteGoFile(filename, pkg string, b []byte) {
+	w, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer w.Close()
+	if _, err = WriteGo(w, pkg, "", b); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+func insertVersion(filename, version string) string {
+	suffix := ".go"
+	if strings.HasSuffix(filename, "_test.go") {
+		suffix = "_test.go"
+	}
+	return fmt.Sprint(filename[:len(filename)-len(suffix)], version, suffix)
+}
+
+// WriteVersionedGoFile prepends a standard file comment, adds build tags to
+// version the file for the current Unicode version, and package statement to
+// the given bytes, applies gofmt, and writes them to a file with the given
+// name. It will call log.Fatal if there are any errors.
+func WriteVersionedGoFile(filename, pkg string, b []byte) {
+	tags := buildTags()
+	if tags != "" {
+		filename = insertVersion(filename, UnicodeVersion())
+	}
+	w, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer w.Close()
+	if _, err = WriteGo(w, pkg, tags, b); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+// WriteGo prepends a standard file comment and package statement to the given
+// bytes, applies gofmt, and writes them to w.
+func WriteGo(w io.Writer, pkg, tags string, b []byte) (n int, err error) {
+	src := []byte(header)
+	if tags != "" {
+		src = append(src, fmt.Sprintf("// +build %s\n\n", tags)...)
+	}
+	src = append(src, fmt.Sprintf("package %s\n\n", pkg)...)
+	src = append(src, b...)
+	formatted, err := format.Source(src)
+	if err != nil {
+		// Print the generated code even in case of an error so that the
+		// returned error can be meaningfully interpreted.
+		n, _ = w.Write(src)
+		return n, err
+	}
+	return w.Write(formatted)
+}
+
+// Repackage rewrites a Go file from belonging to package main to belonging to
+// the given package.
+func Repackage(inFile, outFile, pkg string) {
+	src, err := ioutil.ReadFile(inFile)
+	if err != nil {
+		log.Fatalf("reading %s: %v", inFile, err)
+	}
+	const toDelete = "package main\n\n"
+	i := bytes.Index(src, []byte(toDelete))
+	if i < 0 {
+		log.Fatalf("Could not find %q in %s.", toDelete, inFile)
+	}
+	w := &bytes.Buffer{}
+	w.Write(src[i+len(toDelete):])
+	WriteGoFile(outFile, pkg, w.Bytes())
+}
diff --git a/vendor/golang.org/x/text/internal/tag/tag.go b/vendor/golang.org/x/text/internal/tag/tag.go
new file mode 100644
index 0000000..b5d3488
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/tag/tag.go
@@ -0,0 +1,100 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package tag contains functionality handling tags and related data.
+package tag // import "golang.org/x/text/internal/tag"
+
+import "sort"
+
+// An Index converts tags to a compact numeric value.
+//
+// All elements are of size 4. Tags may be up to 4 bytes long. Excess bytes can
+// be used to store additional information about the tag.
+type Index string
+
+// Elem returns the element data at the given index.
+func (s Index) Elem(x int) string {
+	return string(s[x*4 : x*4+4])
+}
+
+// Index reports the index of the given key or -1 if it could not be found.
+// Only the first len(key) bytes from the start of the 4-byte entries will be
+// considered for the search and the first match in Index will be returned.
+func (s Index) Index(key []byte) int {
+	n := len(key)
+	// search the index of the first entry with an equal or higher value than
+	// key in s.
+	index := sort.Search(len(s)/4, func(i int) bool {
+		return cmp(s[i*4:i*4+n], key) != -1
+	})
+	i := index * 4
+	if cmp(s[i:i+len(key)], key) != 0 {
+		return -1
+	}
+	return index
+}
+
+// Next finds the next occurrence of key after index x, which must have been
+// obtained from a call to Index using the same key. It returns x+1 or -1.
+func (s Index) Next(key []byte, x int) int {
+	if x++; x*4 < len(s) && cmp(s[x*4:x*4+len(key)], key) == 0 {
+		return x
+	}
+	return -1
+}
+
+// cmp returns an integer comparing a and b lexicographically.
+func cmp(a Index, b []byte) int {
+	n := len(a)
+	if len(b) < n {
+		n = len(b)
+	}
+	for i, c := range b[:n] {
+		switch {
+		case a[i] > c:
+			return 1
+		case a[i] < c:
+			return -1
+		}
+	}
+	switch {
+	case len(a) < len(b):
+		return -1
+	case len(a) > len(b):
+		return 1
+	}
+	return 0
+}
+
+// Compare returns an integer comparing a and b lexicographically.
+func Compare(a string, b []byte) int {
+	return cmp(Index(a), b)
+}
+
+// FixCase reformats b to the same pattern of cases as form.
+// If returns false if string b is malformed.
+func FixCase(form string, b []byte) bool {
+	if len(form) != len(b) {
+		return false
+	}
+	for i, c := range b {
+		if form[i] <= 'Z' {
+			if c >= 'a' {
+				c -= 'z' - 'Z'
+			}
+			if c < 'A' || 'Z' < c {
+				return false
+			}
+		} else {
+			if c <= 'Z' {
+				c += 'z' - 'Z'
+			}
+			if c < 'a' || 'z' < c {
+				return false
+			}
+		}
+		b[i] = c
+	}
+	return true
+}
diff --git a/vendor/golang.org/x/text/internal/triegen/compact.go b/vendor/golang.org/x/text/internal/triegen/compact.go
new file mode 100644
index 0000000..397b975
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/triegen/compact.go
@@ -0,0 +1,58 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package triegen
+
+// This file defines Compacter and its implementations.
+
+import "io"
+
+// A Compacter generates an alternative, more space-efficient way to store a
+// trie value block. A trie value block holds all possible values for the last
+// byte of a UTF-8 encoded rune. Excluding ASCII characters, a trie value block
+// always has 64 values, as a UTF-8 encoding ends with a byte in [0x80, 0xC0).
+type Compacter interface {
+	// Size returns whether the Compacter could encode the given block as well
+	// as its size in case it can. len(v) is always 64.
+	Size(v []uint64) (sz int, ok bool)
+
+	// Store stores the block using the Compacter's compression method.
+	// It returns a handle with which the block can be retrieved.
+	// len(v) is always 64.
+	Store(v []uint64) uint32
+
+	// Print writes the data structures associated to the given store to w.
+	Print(w io.Writer) error
+
+	// Handler returns the name of a function that gets called during trie
+	// lookup for blocks generated by the Compacter. The function should be of
+	// the form func (n uint32, b byte) uint64, where n is the index returned by
+	// the Compacter's Store method and b is the last byte of the UTF-8
+	// encoding, where 0x80 <= b < 0xC0, for which to do the lookup in the
+	// block.
+	Handler() string
+}
+
+// simpleCompacter is the default Compacter used by builder. It implements a
+// normal trie block.
+type simpleCompacter builder
+
+func (b *simpleCompacter) Size([]uint64) (sz int, ok bool) {
+	return blockSize * b.ValueSize, true
+}
+
+func (b *simpleCompacter) Store(v []uint64) uint32 {
+	h := uint32(len(b.ValueBlocks) - blockOffset)
+	b.ValueBlocks = append(b.ValueBlocks, v)
+	return h
+}
+
+func (b *simpleCompacter) Print(io.Writer) error {
+	// Structures are printed in print.go.
+	return nil
+}
+
+func (b *simpleCompacter) Handler() string {
+	panic("Handler should be special-cased for this Compacter")
+}
diff --git a/vendor/golang.org/x/text/internal/triegen/print.go b/vendor/golang.org/x/text/internal/triegen/print.go
new file mode 100644
index 0000000..8d9f120
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/triegen/print.go
@@ -0,0 +1,251 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package triegen
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+	"text/template"
+)
+
+// print writes all the data structures as well as the code necessary to use the
+// trie to w.
+func (b *builder) print(w io.Writer) error {
+	b.Stats.NValueEntries = len(b.ValueBlocks) * blockSize
+	b.Stats.NValueBytes = len(b.ValueBlocks) * blockSize * b.ValueSize
+	b.Stats.NIndexEntries = len(b.IndexBlocks) * blockSize
+	b.Stats.NIndexBytes = len(b.IndexBlocks) * blockSize * b.IndexSize
+	b.Stats.NHandleBytes = len(b.Trie) * 2 * b.IndexSize
+
+	// If we only have one root trie, all starter blocks are at position 0 and
+	// we can access the arrays directly.
+	if len(b.Trie) == 1 {
+		// At this point we cannot refer to the generated tables directly.
+		b.ASCIIBlock = b.Name + "Values"
+		b.StarterBlock = b.Name + "Index"
+	} else {
+		// Otherwise we need to have explicit starter indexes in the trie
+		// structure.
+		b.ASCIIBlock = "t.ascii"
+		b.StarterBlock = "t.utf8Start"
+	}
+
+	b.SourceType = "[]byte"
+	if err := lookupGen.Execute(w, b); err != nil {
+		return err
+	}
+
+	b.SourceType = "string"
+	if err := lookupGen.Execute(w, b); err != nil {
+		return err
+	}
+
+	if err := trieGen.Execute(w, b); err != nil {
+		return err
+	}
+
+	for _, c := range b.Compactions {
+		if err := c.c.Print(w); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func printValues(n int, values []uint64) string {
+	w := &bytes.Buffer{}
+	boff := n * blockSize
+	fmt.Fprintf(w, "\t// Block %#x, offset %#x", n, boff)
+	var newline bool
+	for i, v := range values {
+		if i%6 == 0 {
+			newline = true
+		}
+		if v != 0 {
+			if newline {
+				fmt.Fprintf(w, "\n")
+				newline = false
+			}
+			fmt.Fprintf(w, "\t%#02x:%#04x, ", boff+i, v)
+		}
+	}
+	return w.String()
+}
+
+func printIndex(b *builder, nr int, n *node) string {
+	w := &bytes.Buffer{}
+	boff := nr * blockSize
+	fmt.Fprintf(w, "\t// Block %#x, offset %#x", nr, boff)
+	var newline bool
+	for i, c := range n.children {
+		if i%8 == 0 {
+			newline = true
+		}
+		if c != nil {
+			v := b.Compactions[c.index.compaction].Offset + uint32(c.index.index)
+			if v != 0 {
+				if newline {
+					fmt.Fprintf(w, "\n")
+					newline = false
+				}
+				fmt.Fprintf(w, "\t%#02x:%#02x, ", boff+i, v)
+			}
+		}
+	}
+	return w.String()
+}
+
+var (
+	trieGen = template.Must(template.New("trie").Funcs(template.FuncMap{
+		"printValues": printValues,
+		"printIndex":  printIndex,
+		"title":       strings.Title,
+		"dec":         func(x int) int { return x - 1 },
+		"psize": func(n int) string {
+			return fmt.Sprintf("%d bytes (%.2f KiB)", n, float64(n)/1024)
+		},
+	}).Parse(trieTemplate))
+	lookupGen = template.Must(template.New("lookup").Parse(lookupTemplate))
+)
+
+// TODO: consider the return type of lookup. It could be uint64, even if the
+// internal value type is smaller. We will have to verify this with the
+// performance of unicode/norm, which is very sensitive to such changes.
+const trieTemplate = `{{$b := .}}{{$multi := gt (len .Trie) 1}}
+// {{.Name}}Trie. Total size: {{psize .Size}}. Checksum: {{printf "%08x" .Checksum}}.
+type {{.Name}}Trie struct { {{if $multi}}
+	ascii []{{.ValueType}} // index for ASCII bytes
+	utf8Start  []{{.IndexType}} // index for UTF-8 bytes >= 0xC0
+{{end}}}
+
+func new{{title .Name}}Trie(i int) *{{.Name}}Trie { {{if $multi}}
+	h := {{.Name}}TrieHandles[i]
+	return &{{.Name}}Trie{ {{.Name}}Values[uint32(h.ascii)<<6:], {{.Name}}Index[uint32(h.multi)<<6:] }
+}
+
+type {{.Name}}TrieHandle struct {
+	ascii, multi {{.IndexType}}
+}
+
+// {{.Name}}TrieHandles: {{len .Trie}} handles, {{.Stats.NHandleBytes}} bytes
+var {{.Name}}TrieHandles = [{{len .Trie}}]{{.Name}}TrieHandle{
+{{range .Trie}}	{ {{.ASCIIIndex}}, {{.StarterIndex}} }, // {{printf "%08x" .Checksum}}: {{.Name}}
+{{end}}}{{else}}
+	return &{{.Name}}Trie{}
+}
+{{end}}
+// lookupValue determines the type of block n and looks up the value for b.
+func (t *{{.Name}}Trie) lookupValue(n uint32, b byte) {{.ValueType}}{{$last := dec (len .Compactions)}} {
+	switch { {{range $i, $c := .Compactions}}
+		{{if eq $i $last}}default{{else}}case n < {{$c.Cutoff}}{{end}}:{{if ne $i 0}}
+			n -= {{$c.Offset}}{{end}}
+			return {{print $b.ValueType}}({{$c.Handler}}){{end}}
+	}
+}
+
+// {{.Name}}Values: {{len .ValueBlocks}} blocks, {{.Stats.NValueEntries}} entries, {{.Stats.NValueBytes}} bytes
+// The third block is the zero block.
+var {{.Name}}Values = [{{.Stats.NValueEntries}}]{{.ValueType}} {
+{{range $i, $v := .ValueBlocks}}{{printValues $i $v}}
+{{end}}}
+
+// {{.Name}}Index: {{len .IndexBlocks}} blocks, {{.Stats.NIndexEntries}} entries, {{.Stats.NIndexBytes}} bytes
+// Block 0 is the zero block.
+var {{.Name}}Index = [{{.Stats.NIndexEntries}}]{{.IndexType}} {
+{{range $i, $v := .IndexBlocks}}{{printIndex $b $i $v}}
+{{end}}}
+`
+
+// TODO: consider allowing zero-length strings after evaluating performance with
+// unicode/norm.
+const lookupTemplate = `
+// lookup{{if eq .SourceType "string"}}String{{end}} returns the trie value for the first UTF-8 encoding in s and
+// the width in bytes of this encoding. The size will be 0 if s does not
+// hold enough bytes to complete the encoding. len(s) must be greater than 0.
+func (t *{{.Name}}Trie) lookup{{if eq .SourceType "string"}}String{{end}}(s {{.SourceType}}) (v {{.ValueType}}, sz int) {
+	c0 := s[0]
+	switch {
+	case c0 < 0x80: // is ASCII
+		return {{.ASCIIBlock}}[c0], 1
+	case c0 < 0xC2:
+		return 0, 1  // Illegal UTF-8: not a starter, not ASCII.
+	case c0 < 0xE0: // 2-byte UTF-8
+		if len(s) < 2 {
+			return 0, 0
+		}
+		i := {{.StarterBlock}}[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return 0, 1 // Illegal UTF-8: not a continuation byte.
+		}
+		return t.lookupValue(uint32(i), c1), 2
+	case c0 < 0xF0: // 3-byte UTF-8
+		if len(s) < 3 {
+			return 0, 0
+		}
+		i := {{.StarterBlock}}[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return 0, 1 // Illegal UTF-8: not a continuation byte.
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = {{.Name}}Index[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return 0, 2 // Illegal UTF-8: not a continuation byte.
+		}
+		return t.lookupValue(uint32(i), c2), 3
+	case c0 < 0xF8: // 4-byte UTF-8
+		if len(s) < 4 {
+			return 0, 0
+		}
+		i := {{.StarterBlock}}[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return 0, 1 // Illegal UTF-8: not a continuation byte.
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = {{.Name}}Index[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return 0, 2 // Illegal UTF-8: not a continuation byte.
+		}
+		o = uint32(i)<<6 + uint32(c2)
+		i = {{.Name}}Index[o]
+		c3 := s[3]
+		if c3 < 0x80 || 0xC0 <= c3 {
+			return 0, 3 // Illegal UTF-8: not a continuation byte.
+		}
+		return t.lookupValue(uint32(i), c3), 4
+	}
+	// Illegal rune
+	return 0, 1
+}
+
+// lookup{{if eq .SourceType "string"}}String{{end}}Unsafe returns the trie value for the first UTF-8 encoding in s.
+// s must start with a full and valid UTF-8 encoded rune.
+func (t *{{.Name}}Trie) lookup{{if eq .SourceType "string"}}String{{end}}Unsafe(s {{.SourceType}}) {{.ValueType}} {
+	c0 := s[0]
+	if c0 < 0x80 { // is ASCII
+		return {{.ASCIIBlock}}[c0]
+	}
+	i := {{.StarterBlock}}[c0]
+	if c0 < 0xE0 { // 2-byte UTF-8
+		return t.lookupValue(uint32(i), s[1])
+	}
+	i = {{.Name}}Index[uint32(i)<<6+uint32(s[1])]
+	if c0 < 0xF0 { // 3-byte UTF-8
+		return t.lookupValue(uint32(i), s[2])
+	}
+	i = {{.Name}}Index[uint32(i)<<6+uint32(s[2])]
+	if c0 < 0xF8 { // 4-byte UTF-8
+		return t.lookupValue(uint32(i), s[3])
+	}
+	return 0
+}
+`
diff --git a/vendor/golang.org/x/text/internal/triegen/triegen.go b/vendor/golang.org/x/text/internal/triegen/triegen.go
new file mode 100644
index 0000000..adb0108
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/triegen/triegen.go
@@ -0,0 +1,494 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package triegen implements a code generator for a trie for associating
+// unsigned integer values with UTF-8 encoded runes.
+//
+// Many of the go.text packages use tries for storing per-rune information.  A
+// trie is especially useful if many of the runes have the same value. If this
+// is the case, many blocks can be expected to be shared allowing for
+// information on many runes to be stored in little space.
+//
+// As most of the lookups are done directly on []byte slices, the tries use the
+// UTF-8 bytes directly for the lookup. This saves a conversion from UTF-8 to
+// runes and contributes a little bit to better performance. It also naturally
+// provides a fast path for ASCII.
+//
+// Space is also an issue. There are many code points defined in Unicode and as
+// a result tables can get quite large. So every byte counts. The triegen
+// package automatically chooses the smallest integer values to represent the
+// tables. Compacters allow further compression of the trie by allowing for
+// alternative representations of individual trie blocks.
+//
+// triegen allows generating multiple tries as a single structure. This is
+// useful when, for example, one wants to generate tries for several languages
+// that have a lot of values in common. Some existing libraries for
+// internationalization store all per-language data as a dynamically loadable
+// chunk. The go.text packages are designed with the assumption that the user
+// typically wants to compile in support for all supported languages, in line
+// with the approach common to Go to create a single standalone binary. The
+// multi-root trie approach can give significant storage savings in this
+// scenario.
+//
+// triegen generates both tables and code. The code is optimized to use the
+// automatically chosen data types. The following code is generated for a Trie
+// or multiple Tries named "foo":
+//	- type fooTrie
+//		The trie type.
+//
+//	- func newFooTrie(x int) *fooTrie
+//		Trie constructor, where x is the index of the trie passed to Gen.
+//
+//	- func (t *fooTrie) lookup(s []byte) (v uintX, sz int)
+//		The lookup method, where uintX is automatically chosen.
+//
+//	- func lookupString, lookupUnsafe and lookupStringUnsafe
+//		Variants of the above.
+//
+//	- var fooValues and fooIndex and any tables generated by Compacters.
+//		The core trie data.
+//
+//	- var fooTrieHandles
+//		Indexes of starter blocks in case of multiple trie roots.
+//
+// It is recommended that users test the generated trie by checking the returned
+// value for every rune. Such exhaustive tests are possible as the the number of
+// runes in Unicode is limited.
+package triegen // import "golang.org/x/text/internal/triegen"
+
+// TODO: Arguably, the internally optimized data types would not have to be
+// exposed in the generated API. We could also investigate not generating the
+// code, but using it through a package. We would have to investigate the impact
+// on performance of making such change, though. For packages like unicode/norm,
+// small changes like this could tank performance.
+
+import (
+	"encoding/binary"
+	"fmt"
+	"hash/crc64"
+	"io"
+	"log"
+	"unicode/utf8"
+)
+
+// builder builds a set of tries for associating values with runes. The set of
+// tries can share common index and value blocks.
+type builder struct {
+	Name string
+
+	// ValueType is the type of the trie values looked up.
+	ValueType string
+
+	// ValueSize is the byte size of the ValueType.
+	ValueSize int
+
+	// IndexType is the type of trie index values used for all UTF-8 bytes of
+	// a rune except the last one.
+	IndexType string
+
+	// IndexSize is the byte size of the IndexType.
+	IndexSize int
+
+	// SourceType is used when generating the lookup functions. If the user
+	// requests StringSupport, all lookup functions will be generated for
+	// string input as well.
+	SourceType string
+
+	Trie []*Trie
+
+	IndexBlocks []*node
+	ValueBlocks [][]uint64
+	Compactions []compaction
+	Checksum    uint64
+
+	ASCIIBlock   string
+	StarterBlock string
+
+	indexBlockIdx map[uint64]int
+	valueBlockIdx map[uint64]nodeIndex
+	asciiBlockIdx map[uint64]int
+
+	// Stats are used to fill out the template.
+	Stats struct {
+		NValueEntries int
+		NValueBytes   int
+		NIndexEntries int
+		NIndexBytes   int
+		NHandleBytes  int
+	}
+
+	err error
+}
+
+// A nodeIndex encodes the index of a node, which is defined by the compaction
+// which stores it and an index within the compaction. For internal nodes, the
+// compaction is always 0.
+type nodeIndex struct {
+	compaction int
+	index      int
+}
+
+// compaction keeps track of stats used for the compaction.
+type compaction struct {
+	c         Compacter
+	blocks    []*node
+	maxHandle uint32
+	totalSize int
+
+	// Used by template-based generator and thus exported.
+	Cutoff  uint32
+	Offset  uint32
+	Handler string
+}
+
+func (b *builder) setError(err error) {
+	if b.err == nil {
+		b.err = err
+	}
+}
+
+// An Option can be passed to Gen.
+type Option func(b *builder) error
+
+// Compact configures the trie generator to use the given Compacter.
+func Compact(c Compacter) Option {
+	return func(b *builder) error {
+		b.Compactions = append(b.Compactions, compaction{
+			c:       c,
+			Handler: c.Handler() + "(n, b)"})
+		return nil
+	}
+}
+
+// Gen writes Go code for a shared trie lookup structure to w for the given
+// Tries. The generated trie type will be called nameTrie. newNameTrie(x) will
+// return the *nameTrie for tries[x]. A value can be looked up by using one of
+// the various lookup methods defined on nameTrie. It returns the table size of
+// the generated trie.
+func Gen(w io.Writer, name string, tries []*Trie, opts ...Option) (sz int, err error) {
+	// The index contains two dummy blocks, followed by the zero block. The zero
+	// block is at offset 0x80, so that the offset for the zero block for
+	// continuation bytes is 0.
+	b := &builder{
+		Name:        name,
+		Trie:        tries,
+		IndexBlocks: []*node{{}, {}, {}},
+		Compactions: []compaction{{
+			Handler: name + "Values[n<<6+uint32(b)]",
+		}},
+		// The 0 key in indexBlockIdx and valueBlockIdx is the hash of the zero
+		// block.
+		indexBlockIdx: map[uint64]int{0: 0},
+		valueBlockIdx: map[uint64]nodeIndex{0: {}},
+		asciiBlockIdx: map[uint64]int{},
+	}
+	b.Compactions[0].c = (*simpleCompacter)(b)
+
+	for _, f := range opts {
+		if err := f(b); err != nil {
+			return 0, err
+		}
+	}
+	b.build()
+	if b.err != nil {
+		return 0, b.err
+	}
+	if err = b.print(w); err != nil {
+		return 0, err
+	}
+	return b.Size(), nil
+}
+
+// A Trie represents a single root node of a trie. A builder may build several
+// overlapping tries at once.
+type Trie struct {
+	root *node
+
+	hiddenTrie
+}
+
+// hiddenTrie contains values we want to be visible to the template generator,
+// but hidden from the API documentation.
+type hiddenTrie struct {
+	Name         string
+	Checksum     uint64
+	ASCIIIndex   int
+	StarterIndex int
+}
+
+// NewTrie returns a new trie root.
+func NewTrie(name string) *Trie {
+	return &Trie{
+		&node{
+			children: make([]*node, blockSize),
+			values:   make([]uint64, utf8.RuneSelf),
+		},
+		hiddenTrie{Name: name},
+	}
+}
+
+// Gen is a convenience wrapper around the Gen func passing t as the only trie
+// and uses the name passed to NewTrie. It returns the size of the generated
+// tables.
+func (t *Trie) Gen(w io.Writer, opts ...Option) (sz int, err error) {
+	return Gen(w, t.Name, []*Trie{t}, opts...)
+}
+
+// node is a node of the intermediate trie structure.
+type node struct {
+	// children holds this node's children. It is always of length 64.
+	// A child node may be nil.
+	children []*node
+
+	// values contains the values of this node. If it is non-nil, this node is
+	// either a root or leaf node:
+	// For root nodes, len(values) == 128 and it maps the bytes in [0x00, 0x7F].
+	// For leaf nodes, len(values) ==  64 and it maps the bytes in [0x80, 0xBF].
+	values []uint64
+
+	index nodeIndex
+}
+
+// Insert associates value with the given rune. Insert will panic if a non-zero
+// value is passed for an invalid rune.
+func (t *Trie) Insert(r rune, value uint64) {
+	if value == 0 {
+		return
+	}
+	s := string(r)
+	if []rune(s)[0] != r && value != 0 {
+		// Note: The UCD tables will always assign what amounts to a zero value
+		// to a surrogate. Allowing a zero value for an illegal rune allows
+		// users to iterate over [0..MaxRune] without having to explicitly
+		// exclude surrogates, which would be tedious.
+		panic(fmt.Sprintf("triegen: non-zero value for invalid rune %U", r))
+	}
+	if len(s) == 1 {
+		// It is a root node value (ASCII).
+		t.root.values[s[0]] = value
+		return
+	}
+
+	n := t.root
+	for ; len(s) > 1; s = s[1:] {
+		if n.children == nil {
+			n.children = make([]*node, blockSize)
+		}
+		p := s[0] % blockSize
+		c := n.children[p]
+		if c == nil {
+			c = &node{}
+			n.children[p] = c
+		}
+		if len(s) > 2 && c.values != nil {
+			log.Fatalf("triegen: insert(%U): found internal node with values", r)
+		}
+		n = c
+	}
+	if n.values == nil {
+		n.values = make([]uint64, blockSize)
+	}
+	if n.children != nil {
+		log.Fatalf("triegen: insert(%U): found leaf node that also has child nodes", r)
+	}
+	n.values[s[0]-0x80] = value
+}
+
+// Size returns the number of bytes the generated trie will take to store. It
+// needs to be exported as it is used in the templates.
+func (b *builder) Size() int {
+	// Index blocks.
+	sz := len(b.IndexBlocks) * blockSize * b.IndexSize
+
+	// Skip the first compaction, which represents the normal value blocks, as
+	// its totalSize does not account for the ASCII blocks, which are managed
+	// separately.
+	sz += len(b.ValueBlocks) * blockSize * b.ValueSize
+	for _, c := range b.Compactions[1:] {
+		sz += c.totalSize
+	}
+
+	// TODO: this computation does not account for the fixed overhead of a using
+	// a compaction, either code or data. As for data, though, the typical
+	// overhead of data is in the order of bytes (2 bytes for cases). Further,
+	// the savings of using a compaction should anyway be substantial for it to
+	// be worth it.
+
+	// For multi-root tries, we also need to account for the handles.
+	if len(b.Trie) > 1 {
+		sz += 2 * b.IndexSize * len(b.Trie)
+	}
+	return sz
+}
+
+func (b *builder) build() {
+	// Compute the sizes of the values.
+	var vmax uint64
+	for _, t := range b.Trie {
+		vmax = maxValue(t.root, vmax)
+	}
+	b.ValueType, b.ValueSize = getIntType(vmax)
+
+	// Compute all block allocations.
+	// TODO: first compute the ASCII blocks for all tries and then the other
+	// nodes. ASCII blocks are more restricted in placement, as they require two
+	// blocks to be placed consecutively. Processing them first may improve
+	// sharing (at least one zero block can be expected to be saved.)
+	for _, t := range b.Trie {
+		b.Checksum += b.buildTrie(t)
+	}
+
+	// Compute the offsets for all the Compacters.
+	offset := uint32(0)
+	for i := range b.Compactions {
+		c := &b.Compactions[i]
+		c.Offset = offset
+		offset += c.maxHandle + 1
+		c.Cutoff = offset
+	}
+
+	// Compute the sizes of indexes.
+	// TODO: different byte positions could have different sizes. So far we have
+	// not found a case where this is beneficial.
+	imax := uint64(b.Compactions[len(b.Compactions)-1].Cutoff)
+	for _, ib := range b.IndexBlocks {
+		if x := uint64(ib.index.index); x > imax {
+			imax = x
+		}
+	}
+	b.IndexType, b.IndexSize = getIntType(imax)
+}
+
+func maxValue(n *node, max uint64) uint64 {
+	if n == nil {
+		return max
+	}
+	for _, c := range n.children {
+		max = maxValue(c, max)
+	}
+	for _, v := range n.values {
+		if max < v {
+			max = v
+		}
+	}
+	return max
+}
+
+func getIntType(v uint64) (string, int) {
+	switch {
+	case v < 1<<8:
+		return "uint8", 1
+	case v < 1<<16:
+		return "uint16", 2
+	case v < 1<<32:
+		return "uint32", 4
+	}
+	return "uint64", 8
+}
+
+const (
+	blockSize = 64
+
+	// Subtract two blocks to offset 0x80, the first continuation byte.
+	blockOffset = 2
+
+	// Subtract three blocks to offset 0xC0, the first non-ASCII starter.
+	rootBlockOffset = 3
+)
+
+var crcTable = crc64.MakeTable(crc64.ISO)
+
+func (b *builder) buildTrie(t *Trie) uint64 {
+	n := t.root
+
+	// Get the ASCII offset. For the first trie, the ASCII block will be at
+	// position 0.
+	hasher := crc64.New(crcTable)
+	binary.Write(hasher, binary.BigEndian, n.values)
+	hash := hasher.Sum64()
+
+	v, ok := b.asciiBlockIdx[hash]
+	if !ok {
+		v = len(b.ValueBlocks)
+		b.asciiBlockIdx[hash] = v
+
+		b.ValueBlocks = append(b.ValueBlocks, n.values[:blockSize], n.values[blockSize:])
+		if v == 0 {
+			// Add the zero block at position 2 so that it will be assigned a
+			// zero reference in the lookup blocks.
+			// TODO: always do this? This would allow us to remove a check from
+			// the trie lookup, but at the expense of extra space. Analyze
+			// performance for unicode/norm.
+			b.ValueBlocks = append(b.ValueBlocks, make([]uint64, blockSize))
+		}
+	}
+	t.ASCIIIndex = v
+
+	// Compute remaining offsets.
+	t.Checksum = b.computeOffsets(n, true)
+	// We already subtracted the normal blockOffset from the index. Subtract the
+	// difference for starter bytes.
+	t.StarterIndex = n.index.index - (rootBlockOffset - blockOffset)
+	return t.Checksum
+}
+
+func (b *builder) computeOffsets(n *node, root bool) uint64 {
+	// For the first trie, the root lookup block will be at position 3, which is
+	// the offset for UTF-8 non-ASCII starter bytes.
+	first := len(b.IndexBlocks) == rootBlockOffset
+	if first {
+		b.IndexBlocks = append(b.IndexBlocks, n)
+	}
+
+	// We special-case the cases where all values recursively are 0. This allows
+	// for the use of a zero block to which all such values can be directed.
+	hash := uint64(0)
+	if n.children != nil || n.values != nil {
+		hasher := crc64.New(crcTable)
+		for _, c := range n.children {
+			var v uint64
+			if c != nil {
+				v = b.computeOffsets(c, false)
+			}
+			binary.Write(hasher, binary.BigEndian, v)
+		}
+		binary.Write(hasher, binary.BigEndian, n.values)
+		hash = hasher.Sum64()
+	}
+
+	if first {
+		b.indexBlockIdx[hash] = rootBlockOffset - blockOffset
+	}
+
+	// Compacters don't apply to internal nodes.
+	if n.children != nil {
+		v, ok := b.indexBlockIdx[hash]
+		if !ok {
+			v = len(b.IndexBlocks) - blockOffset
+			b.IndexBlocks = append(b.IndexBlocks, n)
+			b.indexBlockIdx[hash] = v
+		}
+		n.index = nodeIndex{0, v}
+	} else {
+		h, ok := b.valueBlockIdx[hash]
+		if !ok {
+			bestI, bestSize := 0, blockSize*b.ValueSize
+			for i, c := range b.Compactions[1:] {
+				if sz, ok := c.c.Size(n.values); ok && bestSize > sz {
+					bestI, bestSize = i+1, sz
+				}
+			}
+			c := &b.Compactions[bestI]
+			c.totalSize += bestSize
+			v := c.c.Store(n.values)
+			if c.maxHandle < v {
+				c.maxHandle = v
+			}
+			h = nodeIndex{bestI, int(v)}
+			b.valueBlockIdx[hash] = h
+		}
+		n.index = h
+	}
+	return hash
+}
diff --git a/vendor/golang.org/x/text/internal/ucd/ucd.go b/vendor/golang.org/x/text/internal/ucd/ucd.go
new file mode 100644
index 0000000..8c45b5f
--- /dev/null
+++ b/vendor/golang.org/x/text/internal/ucd/ucd.go
@@ -0,0 +1,371 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package ucd provides a parser for Unicode Character Database files, the
+// format of which is defined in http://www.unicode.org/reports/tr44/. See
+// http://www.unicode.org/Public/UCD/latest/ucd/ for example files.
+//
+// It currently does not support substitutions of missing fields.
+package ucd // import "golang.org/x/text/internal/ucd"
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// UnicodeData.txt fields.
+const (
+	CodePoint = iota
+	Name
+	GeneralCategory
+	CanonicalCombiningClass
+	BidiClass
+	DecompMapping
+	DecimalValue
+	DigitValue
+	NumericValue
+	BidiMirrored
+	Unicode1Name
+	ISOComment
+	SimpleUppercaseMapping
+	SimpleLowercaseMapping
+	SimpleTitlecaseMapping
+)
+
+// Parse calls f for each entry in the given reader of a UCD file. It will close
+// the reader upon return. It will call log.Fatal if any error occurred.
+//
+// This implements the most common usage pattern of using Parser.
+func Parse(r io.ReadCloser, f func(p *Parser)) {
+	defer r.Close()
+
+	p := New(r)
+	for p.Next() {
+		f(p)
+	}
+	if err := p.Err(); err != nil {
+		r.Close() // os.Exit will cause defers not to be called.
+		log.Fatal(err)
+	}
+}
+
+// An Option is used to configure a Parser.
+type Option func(p *Parser)
+
+func keepRanges(p *Parser) {
+	p.keepRanges = true
+}
+
+var (
+	// KeepRanges prevents the expansion of ranges. The raw ranges can be
+	// obtained by calling Range(0) on the parser.
+	KeepRanges Option = keepRanges
+)
+
+// The Part option register a handler for lines starting with a '@'. The text
+// after a '@' is available as the first field. Comments are handled as usual.
+func Part(f func(p *Parser)) Option {
+	return func(p *Parser) {
+		p.partHandler = f
+	}
+}
+
+// The CommentHandler option passes comments that are on a line by itself to
+// a given handler.
+func CommentHandler(f func(s string)) Option {
+	return func(p *Parser) {
+		p.commentHandler = f
+	}
+}
+
+// A Parser parses Unicode Character Database (UCD) files.
+type Parser struct {
+	scanner *bufio.Scanner
+
+	keepRanges bool // Don't expand rune ranges in field 0.
+
+	err     error
+	comment string
+	field   []string
+	// parsedRange is needed in case Range(0) is called more than once for one
+	// field. In some cases this requires scanning ahead.
+	line                 int
+	parsedRange          bool
+	rangeStart, rangeEnd rune
+
+	partHandler    func(p *Parser)
+	commentHandler func(s string)
+}
+
+func (p *Parser) setError(err error, msg string) {
+	if p.err == nil && err != nil {
+		if msg == "" {
+			p.err = fmt.Errorf("ucd:line:%d: %v", p.line, err)
+		} else {
+			p.err = fmt.Errorf("ucd:line:%d:%s: %v", p.line, msg, err)
+		}
+	}
+}
+
+func (p *Parser) getField(i int) string {
+	if i >= len(p.field) {
+		return ""
+	}
+	return p.field[i]
+}
+
+// Err returns a non-nil error if any error occurred during parsing.
+func (p *Parser) Err() error {
+	return p.err
+}
+
+// New returns a Parser for the given Reader.
+func New(r io.Reader, o ...Option) *Parser {
+	p := &Parser{
+		scanner: bufio.NewScanner(r),
+	}
+	for _, f := range o {
+		f(p)
+	}
+	return p
+}
+
+// Next parses the next line in the file. It returns true if a line was parsed
+// and false if it reached the end of the file.
+func (p *Parser) Next() bool {
+	if !p.keepRanges && p.rangeStart < p.rangeEnd {
+		p.rangeStart++
+		return true
+	}
+	p.comment = ""
+	p.field = p.field[:0]
+	p.parsedRange = false
+
+	for p.scanner.Scan() && p.err == nil {
+		p.line++
+		s := p.scanner.Text()
+		if s == "" {
+			continue
+		}
+		if s[0] == '#' {
+			if p.commentHandler != nil {
+				p.commentHandler(strings.TrimSpace(s[1:]))
+			}
+			continue
+		}
+
+		// Parse line
+		if i := strings.IndexByte(s, '#'); i != -1 {
+			p.comment = strings.TrimSpace(s[i+1:])
+			s = s[:i]
+		}
+		if s[0] == '@' {
+			if p.partHandler != nil {
+				p.field = append(p.field, strings.TrimSpace(s[1:]))
+				p.partHandler(p)
+				p.field = p.field[:0]
+			}
+			p.comment = ""
+			continue
+		}
+		for {
+			i := strings.IndexByte(s, ';')
+			if i == -1 {
+				p.field = append(p.field, strings.TrimSpace(s))
+				break
+			}
+			p.field = append(p.field, strings.TrimSpace(s[:i]))
+			s = s[i+1:]
+		}
+		if !p.keepRanges {
+			p.rangeStart, p.rangeEnd = p.getRange(0)
+		}
+		return true
+	}
+	p.setError(p.scanner.Err(), "scanner failed")
+	return false
+}
+
+func parseRune(b string) (rune, error) {
+	if len(b) > 2 && b[0] == 'U' && b[1] == '+' {
+		b = b[2:]
+	}
+	x, err := strconv.ParseUint(b, 16, 32)
+	return rune(x), err
+}
+
+func (p *Parser) parseRune(s string) rune {
+	x, err := parseRune(s)
+	p.setError(err, "failed to parse rune")
+	return x
+}
+
+// Rune parses and returns field i as a rune.
+func (p *Parser) Rune(i int) rune {
+	if i > 0 || p.keepRanges {
+		return p.parseRune(p.getField(i))
+	}
+	return p.rangeStart
+}
+
+// Runes interprets and returns field i as a sequence of runes.
+func (p *Parser) Runes(i int) (runes []rune) {
+	add := func(s string) {
+		if s = strings.TrimSpace(s); len(s) > 0 {
+			runes = append(runes, p.parseRune(s))
+		}
+	}
+	for b := p.getField(i); ; {
+		i := strings.IndexByte(b, ' ')
+		if i == -1 {
+			add(b)
+			break
+		}
+		add(b[:i])
+		b = b[i+1:]
+	}
+	return
+}
+
+var (
+	errIncorrectLegacyRange = errors.New("ucd: unmatched <* First>")
+
+	// reRange matches one line of a legacy rune range.
+	reRange = regexp.MustCompile("^([0-9A-F]*);<([^,]*), ([^>]*)>(.*)$")
+)
+
+// Range parses and returns field i as a rune range. A range is inclusive at
+// both ends. If the field only has one rune, first and last will be identical.
+// It supports the legacy format for ranges used in UnicodeData.txt.
+func (p *Parser) Range(i int) (first, last rune) {
+	if !p.keepRanges {
+		return p.rangeStart, p.rangeStart
+	}
+	return p.getRange(i)
+}
+
+func (p *Parser) getRange(i int) (first, last rune) {
+	b := p.getField(i)
+	if k := strings.Index(b, ".."); k != -1 {
+		return p.parseRune(b[:k]), p.parseRune(b[k+2:])
+	}
+	// The first field may not be a rune, in which case we may ignore any error
+	// and set the range as 0..0.
+	x, err := parseRune(b)
+	if err != nil {
+		// Disable range parsing henceforth. This ensures that an error will be
+		// returned if the user subsequently will try to parse this field as
+		// a Rune.
+		p.keepRanges = true
+	}
+	// Special case for UnicodeData that was retained for backwards compatibility.
+	if i == 0 && len(p.field) > 1 && strings.HasSuffix(p.field[1], "First>") {
+		if p.parsedRange {
+			return p.rangeStart, p.rangeEnd
+		}
+		mf := reRange.FindStringSubmatch(p.scanner.Text())
+		p.line++
+		if mf == nil || !p.scanner.Scan() {
+			p.setError(errIncorrectLegacyRange, "")
+			return x, x
+		}
+		// Using Bytes would be more efficient here, but Text is a lot easier
+		// and this is not a frequent case.
+		ml := reRange.FindStringSubmatch(p.scanner.Text())
+		if ml == nil || mf[2] != ml[2] || ml[3] != "Last" || mf[4] != ml[4] {
+			p.setError(errIncorrectLegacyRange, "")
+			return x, x
+		}
+		p.rangeStart, p.rangeEnd = x, p.parseRune(p.scanner.Text()[:len(ml[1])])
+		p.parsedRange = true
+		return p.rangeStart, p.rangeEnd
+	}
+	return x, x
+}
+
+// bools recognizes all valid UCD boolean values.
+var bools = map[string]bool{
+	"":      false,
+	"N":     false,
+	"No":    false,
+	"F":     false,
+	"False": false,
+	"Y":     true,
+	"Yes":   true,
+	"T":     true,
+	"True":  true,
+}
+
+// Bool parses and returns field i as a boolean value.
+func (p *Parser) Bool(i int) bool {
+	f := p.getField(i)
+	for s, v := range bools {
+		if f == s {
+			return v
+		}
+	}
+	p.setError(strconv.ErrSyntax, "error parsing bool")
+	return false
+}
+
+// Int parses and returns field i as an integer value.
+func (p *Parser) Int(i int) int {
+	x, err := strconv.ParseInt(string(p.getField(i)), 10, 64)
+	p.setError(err, "error parsing int")
+	return int(x)
+}
+
+// Uint parses and returns field i as an unsigned integer value.
+func (p *Parser) Uint(i int) uint {
+	x, err := strconv.ParseUint(string(p.getField(i)), 10, 64)
+	p.setError(err, "error parsing uint")
+	return uint(x)
+}
+
+// Float parses and returns field i as a decimal value.
+func (p *Parser) Float(i int) float64 {
+	x, err := strconv.ParseFloat(string(p.getField(i)), 64)
+	p.setError(err, "error parsing float")
+	return x
+}
+
+// String parses and returns field i as a string value.
+func (p *Parser) String(i int) string {
+	return string(p.getField(i))
+}
+
+// Strings parses and returns field i as a space-separated list of strings.
+func (p *Parser) Strings(i int) []string {
+	ss := strings.Split(string(p.getField(i)), " ")
+	for i, s := range ss {
+		ss[i] = strings.TrimSpace(s)
+	}
+	return ss
+}
+
+// Comment returns the comments for the current line.
+func (p *Parser) Comment() string {
+	return string(p.comment)
+}
+
+var errUndefinedEnum = errors.New("ucd: undefined enum value")
+
+// Enum interprets and returns field i as a value that must be one of the values
+// in enum.
+func (p *Parser) Enum(i int, enum ...string) string {
+	f := p.getField(i)
+	for _, s := range enum {
+		if f == s {
+			return s
+		}
+	}
+	p.setError(errUndefinedEnum, "error parsing enum")
+	return ""
+}