plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BSL%2Bx%E8%BB%B8%E3%81%AE%E3%83%A9%E3%83%99%E3%83%AB%E3%82%92%E7%B8%A6%E3%81%AB%E8%A1%A8%E7%A4%BA
plugin=diff is not implemented.