smackable: add google:queue support
service: toggle google:queue on service bind/unbind
roster: show presence error as status message.
service: remove unneeded methods
chat window: only bind/unbind if onPause/onResume also happened

The ChatWindow is using bindService to clean notifications as well as to
update google:queue status. onPause/onResume are not reliable because
these are called if a chat window is right behind the lockscreen.
onWindowFocusChanged is not reliable because it is called on popup
dialogs / context menu opening. Therefore, both are combined.