Better match scroll to item behavior to UICollectionView
Set indexPath regardless of if it is present in the new model
Assemble a dictionary of views that are to be removed

The previous implementation would check if a given PSTCollectionViewItemKey is
present in the new visible views dictionary. This did not work for the following
case:

Item [0,0]
Item [0,1]
Item [0,2]

Deleting item at [0,1] should result in the alpha fade and eventual removal
from the superview and recycle, but actually since [0,1] is a valid index in the
new layout, [0,2] gets removed instead.

This solution adds views that are to be deleted into a specific NSDictionary
that gets enumerated after all animations are finished. All views contained
inside are recycled.
Add array backing to illustrate deletion
Fix compiler warning - unused variable
Fix double 'batchUpdates'
Uncomment removing deleted view from visible views dictionary

Since `previouslyVisibleViewsDict` is no longer used, we can safely remove
the deleted view from `_allVisibleViewsDict`.
Merge pull request #275 from alexanderedge/master

Delete item causes display corruption in flow layout
Fix compile issue on iOS6
Reformat last animation view changes to now warn on overridden variables
Fix storyboard segues on iOS < 6.0 (closes #121)
Added comment describing downsides of the current implementation
Selection segue is triggered only after the corresponding index path has been added to the _indexPathsForSelectedItems
Fix assertion on deleting and moving same item
Fix assertion message typo
Fix move operations when batched with deletes

Since deletes happen before moves, indexPathBeforeUpdate.item may no
longer point to correct index, so search for the object we're looking
for and use its index.
Add batch update example app
Merge pull request #295 from aburgel/move_fixes

Fix batch updates with NSFetchedResultsController assertions
update podspec
[podspec] Update source tag and remove superfluous public headers.

By default all headers in the `source_files` are assumed to be public.