title: using jqWidgets "jqx-instance" with ngController scope-property syntax
body: <p>How do we use the jqWidgets <code>jqx-instance</code> attribute when used with the ngController scope-property syntax: <code>Controller as myController</code>?  <a href="https://docs.angularjs.org/api/ng/directive/ngController" rel="nofollow">see: Angular docs on ngController</a></p>
  
  <p>for example, this does not work as it should:</p>
  
  <pre><code>&lt;div ng-controller="MainController as main"&gt;
      &lt;jqx-button jqx-instance="main.myButton"&gt;&lt;/jqx-button&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>in the controller, <code>this.myButton</code> should point to the instance, but it is undefined!</p>
  
  <p>Using the other declaration style, i.e., by injecting <code>$scope</code> into the controller, is lame.  With more complex applications we need the more specific syntax to promote clarity, isolation, modularity, etc., especially when different parts are coming from multiple developers.</p>