With this event, users that previously used OpenLayers.Util.onImageLoadError now have an API way to handle tile loading errors with more than just a static background image.
The new events will also be useful for offline storage of tiles, to fall back from an online image to one from local storage.
New events: loaderror for Tile, tileerror for Layer.Grid.
This looks good, no remarks, please merge if you can confirm that relevant tests still pass in IE8, IE9, Chrome, Safari and Firefox. TIA.