title: UICollectionView only calling didSelectItemAtIndexPath if user double taps, will not call when user single taps
body: <p>I have a UICollectionView which is about the size of the screen. The UICollectionViewCells that it displays are the same size as the collectionView.  Each cell has a UIImage which  is the size of the cell.  The CollectionView has paging enabled so essentially it is a full screen photo slideshow that the user can swipe through. </p>
  
  <p>The problem is that<br>
  <code>-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath</code> is only being called if the user taps with two fingers on a cell or long presses with one finger and then releases.  It does not seem to have the default behaviour of single tap selection.  I have not made any changes to the CollectionView gesture recognizer so am having trouble finding a solution to this problem.  </p>