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/google.golang.org/grpc/resolver_conn_wrapper.go b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
index 9d76025..50991ea 100644
--- a/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
+++ b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
@@ -39,7 +39,7 @@
 }
 
 // split2 returns the values from strings.SplitN(s, sep, 2).
-// If sep is not found, it returns ("", s, false) instead.
+// If sep is not found, it returns ("", "", false) instead.
 func split2(s, sep string) (string, string, bool) {
 	spl := strings.SplitN(s, sep, 2)
 	if len(spl) < 2 {