Returns the full path and dimensions of the picture for the aircraft with the ICAO24 and registration passed across or null if no picture exists for the aircraft.

If existingDetail is not supplied or the file's last update or length has changed then the picture details are fetched and a new detail is returned. If existingDetail is supplied and neither the last update or length have changed then the existingDetail is returned without loading the picture.

Loads the aircraft picture with the ICAO24 and registration passed, returning null if the aircraft has no picture. It is the callers responsibility to dispose of the image returned. Note that the image may or may not have been loaded from a file.