title: .chosen.change() - how to figure out whether it was a select or a deselect action
body: <p>How can we figure out whether a change event triggered on a component was a result of a select or a deselect? 
  How can we grab the value of the selected value only or the deselected value only?</p>
  
  <pre><code>$("#airports-select-2").chosen().change(function(event) {
      console.log('select2 change', event, $(event.target).val());
  });
  </code></pre>
  
  <p>This code gives me all the values that have been selected so far on a multiselect component? How can this be changed to only give me value of the newly selected or deselected component?</p>