title: How to close modal window extjs when clicking on mask?
body: <p>If I create a modal window:</p>
  
  <pre><code>Ext.define('myWindow', {
      extend: 'Ext.Container',
      alias: 'widget.myWindow',
      floating: true,
      modal: true,
      listeners:
          'onMaskClick???': { close the window }
      .....
  }
  </code></pre>
  
  <p>How do I know when a user has clicked on the mask outside the window? In Sench Touch, there is a config hideOnMaskTap that lets me specify. What is the event/config for extJS?</p>