title: ExtJS 5.0 cellclick event returns incorrect column
body: <p>I'm trying to use cellclick on a grid where based on a certain column clicked, I want to  run some operations. But every time, it returns a wrong column i.e. if I click on column 0 (first col), it returns the next column. </p>
  
  <pre><code>cellclick: function(view, td, cellIndex, record, tr, rowIndex, e, eOpts ){
      console.info(view.getGridColumns()[cellIndex].dataIndex);
  if(view.getGridColumns()[cellIndex].dataIndex === 'someCol'){
  //do something
      }
  }
  </code></pre>