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/k8s.io/apimachinery/pkg/runtime/types.go b/vendor/k8s.io/apimachinery/pkg/runtime/types.go
index e4515d8..1f7f662 100644
--- a/vendor/k8s.io/apimachinery/pkg/runtime/types.go
+++ b/vendor/k8s.io/apimachinery/pkg/runtime/types.go
@@ -42,6 +42,7 @@
 
 const (
 	ContentTypeJSON string = "application/json"
+	ContentTypeYAML string = "application/yaml"
 )
 
 // RawExtension is used to hold extensions in external versions.