Ensure pod and manifest have a UUID in apiserver

Also has replication controller allow apiserver to automatically assign a UUID

Continues #253 and #199
This is related to the comment below as well: is the purpose of the container manifest ID to allow a client to identify use of that specific manifest in other places in the system?  If so, setting the id here helps a naive client promote that behavior (downstream pods the replication controller creates are distinguishable based on their source).