plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BWinForm%2B%E3%83%98%E3%83%AB%E3%83%97%E3%83%9C%E3%82%BF%E3%83%B3%EF%BC%88HelpButton%EF%BC%89
plugin=diff is not implemented.