Don't rezoom when the app is chilling

Attempts to solve the issue of when to reposition the map to track the user's current location by manipulating the existing flags:

* MapFragment.followMe
* MapzenApplication.moveMapLocation

There is a larger refactor here that we can attempt if this solution proves inadequate or at some later time:

* Remove duplicate followMe and moveMapLocation flags.
* Move FindMeReceiver into MapController.
* Add logic to MapController to decide whether to reposition the map on location update.