plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BRTT%2B%E8%87%AA%E5%8A%A8%E5%88%9D%E5%A7%8B%E5%8C%96%E6%9C%BA%E5%88%B6
plugin=diff is not implemented.