title: extjs change panel title on an event
body: <p>I have a grid panel like this</p>
  
  <pre><code>Ext.define('sCon.view.SalesGrid',{
          extend: 'Ext.grid.GridPanel',
          title: 'Sales Data',
  
          //other params   
  
          initComponent: function(){
              this.callParent(arguments);
          }
      });
  </code></pre>
  
  <p>On a click event, I want to change the title of this panel. My code inside the controller looks like this.</p>
  
  <pre><code>Ext.define('sCon.controller.SalesGridController', {
          extend: 'Ext.app.Controller',
          views: ['SalesGrid'],
  
          // other handlers
  
          changeTitle: function(newTitle){
              this.getView('SalesGrid').setTitle('title_changed');
          }
  </code></pre>
  
  <p>Currently it says that it does not have a function as setTitle(). But the docs say that grid panel has setTitle() function. I also tried changing the title using the 'title' variable like</p>
  
  <pre><code> changeTitle: function(newTitle){
              this.getView('SalesGrid').title = 'title_changed';
  </code></pre>
  
  <p>Neither works.. Please help.</p>