title: add textfield and button for grid cell edit with extjs
body: <p>I'd like to use extjs grid cell edit function, besides textfield, datepicker, I also need a textfield with a button in the right to trigger a picklist modal window. It looks like to datepicker which has a calendar icon in a textfield in the right.</p>
  
  <p>I tried fieldcontainer to combine a textfield with a button, however, it doesn't work. Thanks a lot for help!</p>
  
  <pre><code>Ext.define('CellPicklist', {
      extend: 'Ext.form.FieldContainer',
      xtype: 'cell-picklist',
      layout: 'hbox',
      width: 200,
      items: [{
              xtype: 'textfield',
          }, {
              xtype: 'button'
          }]
  });
  
  columns: [{dataIndex: 'id',hidden: true},{text: 'Name', dataIndex: 'name', flex: 1, editor: 'cell-picklist'}]
  </code></pre>