Automatic merge from submit-queue

replace global registry in apimachinery with global registry in k8s.io/kubernetes

We'd like to remove all globals, but our immediate problem is that a shared registry between k8s.io/kubernetes and k8s.io/client-go doesn't work.  Since client-go makes a copy, we can actually keep a global registry with other globals in pkg/api for now.

@kubernetes/sig-api-machinery-misc @lavalamp @smarterclayton @sttts