Use UICollectionView rather than AQGridView
Update to iOS6 minimum version (as lower versions don't have UICollectionView).
Suggest https://github.com/steipete/PSTCollectionView/tree/master/PSTCollectionView if support for older versions is required.
Fix warnings 'created' by making iOS6 minimum version.
Padding is different using UICollectionView to AQGridView.
Fix update issue (where UICollectionView is not initialised when handleRefresh is finished)
Merge remote-tracking branch 'origin/master' into uicollectionview

Conflicts:
	BakerShelf/ShelfViewController.h
	BakerShelf/ShelfViewController.m
	BakerView/BakerViewController.m
Change the gridView frame on rotation to mimic the display behaviour of AQGridView.
Merge pull request #818 from sdarlington/uicollectionview

Use UICollectionView rather than AQGridView