plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BDotNET%2BGAC%E3%81%AB%E3%82%A2%E3%82%BB%E3%83%B3%E3%83%96%E3%83%AA%E3%82%92%E7%99%BB%E9%8C%B2
plugin=diff is not implemented.