title: Specify animation options in [UIViewControllerTransitionCoordinator animateAlongsideTransition]
body: <p>I've got an iPad app that uses a <code>UICollectionView</code>. On iOS 8, when the device rotates, in <code>viewWillTransitionToSize</code> in my main view controller, I call <code>animateAlongsideTransition</code> on the <code>id&lt;UIViewControllerTransitionCoordinator&gt;</code> parameter and animate the frame change various views in the main view, one of which contains the collection view.</p>
  
  <p>In iOS 7, I use <code>willRotateToInterfaceOrientation:duration:</code> to animate the frame change with <code>[UIView animateWithDuration:delay:options:animations:completion:]</code> call. I pass <code>UIViewAnimationOptionLayoutSubviews</code> as the options parameter, and the collection view animates the re-layout of its items as it resizes. But on iOS 8 with <code>animateAlongsideTransition</code>, only the topmost view gets animated; all of its subviews, including the collection view and its cells, just flash to their new sizes / frames.</p>
  
  <p>My question: <b>how can I use or achieve the effect of <code>UIViewAnimationOptionLayoutSubviews</code> using <code>[animateAlongsideTransition]</code>?</b></p>