Make replica controllers return current state.

Because it leads to lots of unnecessary write load on the data store, and also, it makes compareAndSwap a lot trickier, because suddenly there are writes you care about, and writes you don't care about, or else you have a bunch of unnecessary conflicts.

I think its better hygiene to keep etcd/persistent store the domain of desired state, and current state is always dynamically obtained from the source (possibly with a caching layer for performance)