fix usage of Zone.touchDown(Touch)/touchUp(Touch)

These methods are to be removed, they should not be used, as they were
duplicates that just did assign()/unassign() and mistakenly some other
stuff
fix physics stuff, remove touchDown/touchUp

Zone.touchDown(Touch) and Zone.touchUp(Touch) are not needed, as they
only mistakenly did anything more then just call assign, and as of
commit 54f868c are no longer needed, as the proper calls are made now