OSX: Device list is now persisted; can now remove devices from list. Updated ISyncView.

- SyncDeviceManagerService: Now persists the list of devices to disk.
Several bug fixes.
- Updated SyncWindow UI; updated layout and updated names for controls
and events. Can now remove devices from list; adding devices is not
there yet but some progress has been made.
- Updated ISyncView with proper action names, removed unused actions and
methods.
- Fixed bugs in SyncPresenter (adjusted status message reporting).