Should not start SyncDaemon when started and support "Not running" state.

Indicator needs to query DBus to check whether Ubuntu One is running and show corresponding "Not running" status in case it is not registered on the DBus. Basically we are simulating a part of libsyncdaemon behavior in Maverick.
For Maverick:
 Neither SyncDaemon nor SyncDaemon.UniqueInstance bus name present -> not running
 SyncDaemon.UniqueInstance bus name present, SyncDaemon bus name not present -> starting, not ready for DBus requests
 SyncDaemon bus name present -> DBus listener is up, we are fully working.

For Lucid Lynx we will be only tell the difference between running and not running status.