Proposal: Separate desired and current states

Speculative change for some items from #1200:

* Metadata that applies to resources is split from APIMetadata on non-resource API objects
* Metadata is a sub field of objects
* Labels are on Metadata
* Pod current and desired state is split
* Name is used for pods instead of ID (UID is part of metadata, Name is part of resource) for idempotent creation #148 and #1216 
* PodTemplate is a Metadata carrying object as per #170
 * If replicationController gave way to a generic "replicator", then pod template could be both a nested struct and a real resource.
* A ScheduledPod and ScheduledPodList is what the kubelet sees as per #860
* Non-schema'd k/v values on Metadata as `Config` (better names welcome) as per #1201

Not changed yet:

* ReplicationControllers
* Services

Only look at the second commit, the first is just to get a nice diff from v1beta1.
@bgrant0607 I prefer we interchange those two terms in v1beta3. I am surprised I didn't comment on this one here since I talked this very topic to Vishnu another day:

1) In all systems I have worked before, State is used in FSM
2) It aligns to how docker use
3) it aligns to the internal usage

Moreover, my PR #1268 was merged, which already interchange those two terms for Containers. :-)