title: Extjs 4 listen events for grid's selection model in controller
body: <p>I have a grid and controller for it.
  I try listen for 'select' event for the grid.</p>
  
  <p>The code is:</p>
  
  <pre><code>Ext.define('Icc.controller.Questionnaires', {
    extend: 'Ext.app.Controller',
  
    stores: ['Questionnaires'],
  
    models: ['Questionnaire'],
  
    views: ['QuestionnairesGrid'],
  
    init: function() {
        this.control({
          'mygrid &gt; selectionmodel': {
              // do what I need here
          }
        });
    }
  });
  </code></pre>
  
  <p>How it can be done correctly?</p>