Remove stack from notification center on deinit.
Remove stack from notification center on deinit.

bignerdranch/CoreDataStack,sugar2010/CoreDataStack,gaurav1981/CoreDataStack,binhho/CoreDataStack,phatblat/CoreDataStack,gaurav1981/CoreDataStack,binhho/CoreDataStack,phatblat/CoreDataStack,sugar2010/CoreDataStack,bignerdranch/CoreDataStack,bignerdranch/CoreDataStack,Sully73/CoreDataStack,Sully73/CoreDataStack