plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BC%EF%BC%83%2B%E6%9C%AC%E6%9C%88%E3%81%AE%E6%9C%80%E5%BE%8C%E3%81%AE%E6%97%A5%E3%82%92%E6%B1%82%E3%82%81%E3%82%8B
plugin=diff is not implemented.