title: Renderer for ColumnTree?
body: <p>I'm trying to add a custom renderer to a ColumnTree in Ext JS. Since it appears(?) that this isn't supported, does anyone know of any workaround to use a renderer? Here's a snippet of code - let's just say (hypothetically) that I have a renderer I'd like to use for the documentsVersion tab below - does anyone have any ideas?</p>
  
  <pre><code>return new Ext.tree.ColumnTree({
      autoHeight: false,
      rootVisible: showRoot,
      autoScroll: false,
      id: (!treeId)? window.mainTreeId: treeId,
      loader: (!loader)?window.docTreeLoader:loader,
      columns: [{
           header:"${documentsTitle}",
           width: windowWidth * 0.40
       },
       {
           header:"${documentsVersion}",
           width: windowWidth * 0.10,
           dataIndex:'version'
       },
  </code></pre>
  
  <p>Thanks!</p>