title: sectionInset not working with UICollectionView estimatedItemSize in iOS8 using AutoLayout
body: <p>I can't get my UICollection to properly set <code>sectionInset.left</code> margin when using self-sizing cells with <code>estimatedItemSize</code>. Cells of the UICollectionview should have a somewhat fixed cell height but dynamic width according to the text length.</p>
  
  <p>Here is how it looks when the self-sizing is enabled:</p>
  
  <p><img src="https://i.stack.imgur.com/V9rPf.png" alt="enter image description here"></p>
  
  <p>And when the self-sizing is disabled:</p>
  
  <p><img src="https://i.stack.imgur.com/owQxG.png" alt="enter image description here"></p>
  
  <p>Oddly enough, it seems that <code>sectionInset.right</code> is working, i.e. the margin is added on the right hand side of the UICollectionView.</p>
  
  <p>Here's my custom UICollectionViewFlowLayout, i'm toggling self-size mode using the comment.</p>
  
  <pre><code>class myFlow: UICollectionViewFlowLayout {
      required init(coder: NSCoder) {
      super.init(coder: coder)
  
          self.minimumLineSpacing = 1
  //        self.estimatedItemSize = CGSize(width: 100, height: 35)
          self.sectionInset.left = 20
      }
  </code></pre>
  
  <p>And my custom UICollectionView:</p>
  
  <pre><code>class myCV: UICollectionView {
      required init(coder decoder: NSCoder) {
          super.init(coder: decoder)
  
          self.layer.cornerRadius = 5.0
          self.layer.borderWidth = 1.0
          self.layer.borderColor = UIColor.lightGrayColor().CGColor
  
      }
  }
  </code></pre>
  
  <p>I've laid out the label inside the UICollectionView cell using AutoLayout:</p>
  
  <p><img src="https://i.stack.imgur.com/rkemC.png" alt="enter image description here"></p>