- clean up the sync settings names to:

   (get|set)SyncAutomatically
   (get|set)MasterSyncAutomatically
- change SYNC_EXTRAS_FORCE to SYNC_EXTRAS_MANUAL to mace clear that
  this overrides the .*SyncAutomatically settings
- make ContentResolver methods that call the sync controls methods
  in IContentService so that SDK users can use them
- rename startSync to requestSync to reinforce the fact that a sync
  is not immediately or always started when this method is called
- add an Account parameter to all the sync settings and control methods
- change the sync control methods to take a String authority rather than a Uri uri