title: Callback on notifyiteminserted / notifyitemremoved / notifyitemmoved
body: <p>Looking for something really simple. I looked around in the source code for <code>RecyclerView</code> but couldn't find anything for this. Before I start implementing my own version, I wanted to know if someone knows of anyway to receive a callback on the animation for <code>notifyiteminserted</code>, <code>notifyitemremoved</code>, <code>notifyitemmoved</code>? </p>
  
  <p>This is important because I want to know when the animation has completed. </p>