Collection view crash when using Storyboards

[JSpink95]

When using SQKFetchedCollectionViewController, a crash occurs when loading the UICollectionView. This is due to the UICollectionLayout being nil at the point of creation within the loadView method.

This only occurs when using storyboards because the layout has not been initialised at this point, going back to commit '0a514db' this problem does not occur.

[lukestringer90]

@blork To track down where this may have been fixed in a branch / fork / his head.

[blork]

Some of this is in here (see f0cbec0): https://github.com/3squared/SQKDataKit/tree/collection_view_update

This also contains a commit 54881e3 "Prevent deadlock when the operation is being run on the main thread" which may be a fix for #84 (EDIT: actually no, this was a fix for testing the operations)

[blork]

There is also a much simplified version of SQKFetchedCollectionViewController in a private project. There were so many issues with animation that it was stripped out.