make sure that often forgotten parts are initialized
provided a new method to send a drop

doesn't need to get a full DropMessage object any more.
Merge pull request #139 from jan-schreib/easy-drop

added "comfort" interface for sending drop messages
fix NullPointerException in DropController.handleDrop() when generating ModelObjects from Modules.
Merge pull request #140 from Gottox/master

fix NullPointerException in DropController.handleDrop()