title: setContentEdgeInsets for different states of a UIButton?
body: <p>I'm trying to give a button a depressed look, and to achieve that I need to bump down the title of the button when it's pressed. I think contentEdgeInsets is what I need, but I can't figure out how to set different values depending on the buttons state.</p>
  
  <p>This works:</p>
  
  <pre><code>introButton.contentEdgeInsets = UIEdgeInsetsMake(0, 12, 0, 0);
  </code></pre>
  
  <p>This, however, doesn't:</p>
  
  <pre><code>[introButton setContentEdgeInsets:UIEdgeInsetsMake(0, 12, 0, 0) forState:UIControlStateNormal]; 
  // warning: 'UIButton' may not respond to '-setContentEdgeInsets:forState:'
  </code></pre>