title: UICollectionView not responding after CATransform3D
body: <p>I Have a <code>UIView</code> and inside I have <code>UICollectionView</code> with couple of images. 
  <code>UICollectionView</code> responds to dragging, and I can scroll it without problem.
  When I apply <code>CATransform3D</code> transformation to the <code>UIView</code> which holds the <code>UICollectionView</code> (scale transform effect like on twitter app), the <code>UICollectionView</code> stops responding to the touch, and then scrolling does not work.
  I tried refreshing the <code>UICollectionView</code> after transformation is done, but nothing helps. 
  Any idea?</p>