Clean up initial state / network list sync, remove updateAll

* Removed updateAll calls.  Now we either call sendInitialState (for when the extension and app initially connect) or Social.notifyUI for when an individual network changes
* Change the ui network model to contain a list of all networkNames (strings) and a single onlineNetwork field

Tested in Chrome, grunt test (updated tests, removed tests no longer needed with simpler syncNetwork behavior)