title: Unregister Material Disign Lite component in Backbone view
body: <p>I'm using MDL with Backbone.
  How can i unregister components before removing view that contains any MDL component.</p>
  
  <p>To register components i'm using <code>componentsHandler.upgradeDOM()</code> function from MDL. But without <code>componentsHandler.unregisterComponents()</code> appears memory leak.</p>
  
  <p>I can't get MDL components that associated with current view to unregister them =(</p>