title: UIBarButtonItemStyle Bordered, Done, Plain what is the difference?
body: <p><code>UIBarButtonItemStyle</code> can be: </p>
  
  <ul>
  <li>Bordered</li>
  <li>Done </li>
  <li>Plain</li>
  </ul>
  
  <p><strong>Even reading the documentation I do not know what is the difference and when do I use which?</strong></p>