title: ExtJS 3.x: How to disable the red mark indicating a dirty record in ExtJS EditorGridPanel
body: <p>EditorGridPanel shows a small red triangular corner on the column that is edited to indicate an unsaved record. </p>
  
  <p>Since I am using autoSave, I don't need to indicate the record as dirty/unsaved.</p>
  
  <p>Is there an easy way to disable this ?</p>