title: How do I allow my app to have tracks dropped into it
body: <p>At present when am dragging a track in spotify over the app it doesn't allow dropping. However, the last.fm and moodagent apps do allow this. What code should I be including to make this possible?</p>
  
  <p>I assume it's something to do with <code>EVENTS.LINKSCHANGED</code> but including it doesn't make any difference.</p>