Watch delivers current state for resourceVersion=0

Allows clients to get the current state without having to execute
a get followed by a watch.  Makes integration with action loops
much cleaner.

Split from #846
Ok.  In this case PodList felt more appropriate to return (pods from minions) - we don't treat manifests as individual objects anywhere in the apiserver, so in that case transform is converting the api.ContainerManifestList to an api.PodList, setting the current host (the minion we asked for), and setting the ID appropriately on the Pod.