BoardViewController no longer attempts to remove auto layout constraints during dealloc
BoardViewController no longer attempts to remove auto layout constraints during dealloc

previous experience with ButtonBoxCell has shown that it can be
dangerous to modify the view hierarchy or auto layout constraints during
dealloc, because this might trigger an autorelease somewhere in the
depths of iOS. for this reason, BoardViewController no longer attempts
to remove auto layout constraints during dealloc, instead it simply
makes sure that the array with the constraints is deallocated.

herzbube/littlego,herzbube/littlego,herzbube/littlego,herzbube/littlego,herzbube/littlego