VOL-1497 : Add more control to kv/memory access

- Added kv locking mechanism (etcd only)
- (watch) control path access whenever possible
- (watch) use a transaction for updates and merge with memory
- cleaned up vendoring
- misc changes to fix exceptions found along the way

Amendments:

- Copyright header got removed in auto-generated file
- Changed default locking to false for KV list operation
- Updated backend api to allow the passing of locking parameter

Change-Id: Ie1a55d3ca8b9d92ae71a85ce42bb22fcf1419e2c
diff --git a/vendor/go.uber.org/atomic/atomic.go b/vendor/go.uber.org/atomic/atomic.go
index 290b884..1db6849 100644
--- a/vendor/go.uber.org/atomic/atomic.go
+++ b/vendor/go.uber.org/atomic/atomic.go
@@ -25,6 +25,7 @@
 import (
 	"math"
 	"sync/atomic"
+	"time"
 )
 
 // Int32 is an atomic wrapper around an int32.
@@ -232,6 +233,11 @@
 	return truthy(atomic.LoadUint32(&b.v))
 }
 
+// CAS is an atomic compare-and-swap.
+func (b *Bool) CAS(old, new bool) bool {
+	return atomic.CompareAndSwapUint32(&b.v, boolToInt(old), boolToInt(new))
+}
+
 // Store atomically stores the passed value.
 func (b *Bool) Store(new bool) {
 	atomic.StoreUint32(&b.v, boolToInt(new))
@@ -299,6 +305,47 @@
 	return atomic.CompareAndSwapUint64(&f.v, math.Float64bits(old), math.Float64bits(new))
 }
 
+// Duration is an atomic wrapper around time.Duration
+// https://godoc.org/time#Duration
+type Duration struct {
+	v Int64
+}
+
+// NewDuration creates a Duration.
+func NewDuration(d time.Duration) *Duration {
+	return &Duration{v: *NewInt64(int64(d))}
+}
+
+// Load atomically loads the wrapped value.
+func (d *Duration) Load() time.Duration {
+	return time.Duration(d.v.Load())
+}
+
+// Store atomically stores the passed value.
+func (d *Duration) Store(n time.Duration) {
+	d.v.Store(int64(n))
+}
+
+// Add atomically adds to the wrapped time.Duration and returns the new value.
+func (d *Duration) Add(n time.Duration) time.Duration {
+	return time.Duration(d.v.Add(int64(n)))
+}
+
+// Sub atomically subtracts from the wrapped time.Duration and returns the new value.
+func (d *Duration) Sub(n time.Duration) time.Duration {
+	return time.Duration(d.v.Sub(int64(n)))
+}
+
+// Swap atomically swaps the wrapped time.Duration and returns the old value.
+func (d *Duration) Swap(n time.Duration) time.Duration {
+	return time.Duration(d.v.Swap(int64(n)))
+}
+
+// CAS is an atomic compare-and-swap.
+func (d *Duration) CAS(old, new time.Duration) bool {
+	return d.v.CAS(int64(old), int64(new))
+}
+
 // Value shadows the type of the same name from sync/atomic
 // https://godoc.org/sync/atomic#Value
 type Value struct{ atomic.Value }