plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BManagement%2B%E4%B8%BA%E4%BB%80%E4%B9%88%E7%94%9F%E6%84%8F%E8%B6%8A%E6%9D%A5%E8%B6%8A%E4%B8%8D%E5%A5%BD%E5%81%9A
plugin=diff is not implemented.