title: Refresh existing DataGrid ItemRenderers
body: <p>I have an advancedDataGrid with a custom itemRenderer and a radio button group outside of the grid.  When selecting the radio buttons, i need to update the display state of the itemrenderers.  I'm using a classfactory with the properties attribute to pass in the parameter to the renderers.  </p>
  
  <p>When adding a new row to the grid, the itemrenderer appears with the correct display state, but any renderers that are already on the screen when i change the radio button do not refresh their display.  I've tried calling refresh() on the dataprovider, invalidateList() and invalidateDisplayList() on the datagrid, setting the dataprovider to null and then resetting it, setting the itemrenderer property on the column to null and then resetting it....nothing forces the renderer to update.</p>
  
  <p>The grid is in a tabNavigator so if i change the tab and then come back, the renderers all get redrawn, but this is not an acceptable workaround.  How to you tell the grid to destroy all of its current renderers and re-create them?</p>