Ensure pod and manifest have a UUID in apiserver

Also has replication controller allow apiserver to automatically assign a UUID

Continues #253 and #199
I think we want both this field and controller.DesiredState.PodTemplate.ID to be empty, because we want a fresh ID to be assigned to each pod generated from this template. Am I missing something? Either way, I don't know that it makes much sense for this to match the *controller's* ID?