title: Why does the select2-removing event not trigger in select2 with allowClear?
body: <p>I want to hook an event in my <a href="http://ivaynberg.github.io/select2/#documentation" rel="noreferrer">select2</a> once it gets cleared. The select2 was initalized with <code>allowClear: true</code>. Yet the event</p>
  
  <pre><code>$select.on('select2-removed', function(event) {
      console.log(event);
  });
  </code></pre>
  
  <p>does not trigger when resetting the select2 with the clear button.</p>