Added preference to limit maximum number of parallel running modules
Bugfix: Need to create a new instance of SystemTapTimerTask every time the number of running modules changes from zero to one.
Moved default value for daemon port from Config to xml file
Implemented a full reload of all preferences
Bugfix: Stop ControlDaemon in onDestroy()
Bugfix: Do not start a new activity, if notification is clicked. Just bring the old one to front.
A ClientConnection informs the ControlDaemon about its end of life