title: container control as a grid editor does not update values
body: <p>So I have a grid with two columns, the first has just text, the second needs to have a custom control (with a checkbox and a combo box)</p>
  
  <p>Check the screenie:</p>
  
  <p>Here is a link to a screenie:
  <img src="https://i.stack.imgur.com/7el4U.png" alt="Screenie"></p>
  
  <p>The <strong>Problem</strong>:</p>
  
  <p>When I click update to update the row. The <strong>first column</strong> gets updated, but the second column doesn't</p>
  
  <p>I naively added a <code>getValue()</code> into my custom control but no luck!! (Note: I'm using row editing plugin)</p>
  
  <p>Here is my code:</p>
  
  <pre><code>Ext.define('MainGrid', {
      extend: 'Ext.grid.Panel',
      //defs for all the toolbars and buttons
      plugins: [rowEditing],
      columns: [
                  {
                      xtype: 'rownumberer'
                  },
                  {
                      xtype: 'gridcolumn',
                      text: 'Column Titles',
                      dataIndex: 'ColumnTitle',
                      editor: {
                          xtype: 'textfield',
                      }
                  },
                  {
                      xtype: 'gridcolumn',
                      sortable: false,
                      align: 'center',
                      dataIndex: 'IssueCondition',
                      editor: {
                          xtype: 'reportpopulation'
                      }]
  });
  </code></pre>
  
  <p>The <code>reportpopulation</code> is the <strong>custom control</strong> here. Here is the code for it:</p>
  
  <pre><code>Ext.define('SelectPopulation', {
      extend: 'Ext.container.Container',
      itemId: 'ctrSelectpopulation',
      alias: 'widget.reportpopulation',
      layout: {
          type: 'hbox'
      },
      initComponent: function () {
        //code to add combo box and checkbox snipped
        ....
      },
      getValue: function () {
          //This doesn't work! 
          return "Booo";
      }
  });
  </code></pre>
  
  <p>So clicking Update doesn't :</p>
  
  <ul>
  <li>Is there something I'm missing?</li>
  <li>Should I inherit from FieldBase? Can I use multiple controls and create something like the screenie with FieldBase?</li>
  </ul>