title: UICollectionViewFlowLayout minimumInteritemSpacing doesn't work
body: <p>I've got two problems with my UICollectionView:</p>
  
  <ul>
  <li><code>minimumInteritemSpacing</code> doesn't work</li>
  <li>it overflows horizontally on iOS 6</li>
  </ul>
  
  <p>I set up the layout like this:</p>
  
  <pre><code>UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
  layout.itemSize = CGSizeMake(70.0f, 70.0f);
  layout.scrollDirection = UICollectionViewScrollDirectionVertical;
  layout.minimumLineSpacing = 0.0f;
  layout.minimumInteritemSpacing = 0.0f;
  
  _collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout];
  // I set the size of _collectionView in layoutSubviews:
  // _collectionView.frame = self.bounds;
  
  _collectionView.contentInset = UIEdgeInsetsMake(8.0f, 8.0f, 8.0f, 8.0f);
  </code></pre>
  
  <p>The image shows the result on iOS 6 (on iOS 7 there is no overflow, but the spacing between columns is still not zero)</p>
  
  <p><img src="https://i.stack.imgur.com/3RdKO.png" alt="enter image description here"></p>
  
  <p>I tried this solution <a href="https://gist.github.com/OliverLetterer/5583087" rel="noreferrer">https://gist.github.com/OliverLetterer/5583087</a>, but it doesn't fix anything in my case.</p>