plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BSQLServer%2B%E6%9C%80%E6%96%B0%E6%97%A5%E4%BB%98%E3%81%AE%E3%83%87%E3%83%BC%E3%82%BF%E3%81%AE%E6%8A%BD%E5%87%BA
plugin=diff is not implemented.