title: UILabel is not resizing when table cell appears
body: <p>I have a custom table view cell that display a few labels and a image.
  The main label that has a variable height won't always resize.
  When the table view is first displayed then the labels of the visible cells won't resize but after they will be redisplayed the label will have the correct size.</p>
  
  <p>Table view cell height is set to automatic.
  I tried the solution from here: <a href="http://www.appcoda.com/self-sizing-cells/" rel="nofollow">http://www.appcoda.com/self-sizing-cells/</a> but with no success.
  The label has number of lines = 0;
  i called sizeToFit() / setNeedsLayout() but nothing changes.</p>
  
  <pre><code>let title = (self.posts[indexPath.row] as JSON) ["title"].stringValue as NSString;
  cell.postTitleLabel.preferredMaxLayoutWidth = cell.frame.size.width - 20;
  cell.postTitleLabel.text = title as String;
  cell.setNeedsLayout();
  </code></pre>