suggestion : a PARSE_ERROR event for the asset manager.

This helps clearly determining that the cause for getObject(someDataAsset) returning null is not from an IO_ERROR or the asset not existing in the first place.

 If this data was requested by the app to the user or an external source, we can implement a backup plan by listening for this event such as switching to a default set of data or reloading it from another source, or at least give the user or the external source the proper feedback.