UICollectionView w/ NSFetchedResultsController & NSBlockOperation. Idea originated from Blake Watters (https://github.com/AshFurrow/UICollectionView-NSFetchedResultsController/issues/13)gistfile1.m �, e�U �[ f�U - (void)controllerWillChangeContent:(NSFetchedResultsController *)controller { self.shouldReloadCollectionView = NO; self.blockOperation = [[NSBlockOperation alloc] init]; } - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id<NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)typ
collectionview begin/end coredata updates
