title: Listener not working on Grid Panel - Ext JS
body: <p>This is probably something incredibly simple I'm missing, but I can't figure out why my listener won't work here.</p>
  
  <p>I've defined a grid with a few colums below:</p>
  
  <pre><code>    ...
      {header: 'Privacy', dataIndex: 'PRIVACY_INDICATOR', flex: 3, tdCls: 'grid_cell'},
      {header: 'Lineage', dataIndex: 'popup', renderer: renderPopupIcon, flex: 1, tdCls: 'pop_cell', id: 'lineage_button',
          listeners:  {
              cellclick: function(record) {
                  alert('cell has been clicked');
              }
           }
  }
  </code></pre>
  
  <p>I have tried everything, but I can't seem to get the alert to fire.</p>
  
  <p>Any ideas?</p>