Fnlb/k8s grouper (#563)

* WIP: add k8s grouper

- This shares a great deal of behaviour with allGrouper. Once it's
tested, refactor that to share as much as possible

- Glide hell. Checked in the yaml and lock files but a glide i -v
will be required to bring vendor/ up-to-date. Will address once this
is ready.

* Update README. Make the watch tracking work.

(To follow: add the junk that was pulled in via the glide update.)

* Vendor updates.

* go fmt

* Use the allGrouper with a k8s-backed DBStore instead.

This is much tidier :-)

* Fix up go vet

vendor/golang.org/x/net/route/route_classic.go

@@ -6,7 +6,10 @@
 
 package route
 
-import "syscall"
+import (
+	"runtime"
+	"syscall"
+)
 
 func (m *RouteMessage) marshal() ([]byte, error) {
 	w, ok := wireFormats[m.Type]
@@ -14,6 +17,11 @@ func (m *RouteMessage) marshal() ([]byte, error) {
 		return nil, errUnsupportedMessage
 	}
 	l := w.bodyOff + addrsSpace(m.Addrs)
+	if runtime.GOOS == "darwin" {
+		// Fix stray pointer writes on macOS.
+		// See golang.org/issue/22456.
+		l += 1024
+	}
 	b := make([]byte, l)
 	nativeEndian.PutUint16(b[:2], uint16(l))
 	if m.Version == 0 {