title: UIBarButtonItemStyleDone background image using the iOS 5 appearance API
body: <p>How can I provide a visually distinct bar button item background image for bar buttons with the UIBarButtonItemStyleDone style and the editing state of the Edit/Done button? None of the documented UIControlState values in the UIBarButtonItem appearance proxy's  setBackgroundImage:forState:barMetrics: seem to do the trick.</p>