VOL-1460 Updated core to use voltha-protos instead of local protos
Moved protos to python directory in order to maintain functionaly of containers built there.
Added capability to do local builds of protos
Added instructions on running dep ensure for getting protos.
Updated github.com/golang/protobuf version to v1.3.1

Change-Id: Ia6ef55f07f0d5dcb5b750d7c37b21b71db85bfc4
diff --git a/vendor/golang.org/x/sys/unix/syscall_unix.go b/vendor/golang.org/x/sys/unix/syscall_unix.go
index 33583a2..ae59fba 100644
--- a/vendor/golang.org/x/sys/unix/syscall_unix.go
+++ b/vendor/golang.org/x/sys/unix/syscall_unix.go
@@ -28,6 +28,11 @@
 	errENOENT error = syscall.ENOENT
 )
 
+var (
+	signalNameMapOnce sync.Once
+	signalNameMap     map[string]syscall.Signal
+)
+
 // errnoErr returns common boxed Errno values, to prevent
 // allocations at runtime.
 func errnoErr(e syscall.Errno) error {
@@ -66,6 +71,19 @@
 	return ""
 }
 
+// SignalNum returns the syscall.Signal for signal named s,
+// or 0 if a signal with such name is not found.
+// The signal name should start with "SIG".
+func SignalNum(s string) syscall.Signal {
+	signalNameMapOnce.Do(func() {
+		signalNameMap = make(map[string]syscall.Signal)
+		for _, signal := range signalList {
+			signalNameMap[signal.name] = signal.num
+		}
+	})
+	return signalNameMap[s]
+}
+
 // clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
 func clen(n []byte) int {
 	i := bytes.IndexByte(n, 0)
@@ -377,3 +395,22 @@
 func Exec(argv0 string, argv []string, envv []string) error {
 	return syscall.Exec(argv0, argv, envv)
 }
+
+// Lutimes sets the access and modification times tv on path. If path refers to
+// a symlink, it is not dereferenced and the timestamps are set on the symlink.
+// If tv is nil, the access and modification times are set to the current time.
+// Otherwise tv must contain exactly 2 elements, with access time as the first
+// element and modification time as the second element.
+func Lutimes(path string, tv []Timeval) error {
+	if tv == nil {
+		return UtimesNanoAt(AT_FDCWD, path, nil, AT_SYMLINK_NOFOLLOW)
+	}
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	ts := []Timespec{
+		NsecToTimespec(TimevalToNsec(tv[0])),
+		NsecToTimespec(TimevalToNsec(tv[1])),
+	}
+	return UtimesNanoAt(AT_FDCWD, path, ts, AT_SYMLINK_NOFOLLOW)
+}