Optimized item frame calculations, using C arrays instead of NSArray. Rewritten layoutAttributesForElementsInRect so indexPath and itemAttributes are only allocated when the frame is visible (intersects rect)
Removed old framesForItemsInSection method
Set numberOfSectionsInCollectionView back to 1
Merge pull request #11 from lickylick/master

Optimized item frame calculations and layoutAttributesForElementsInRect