plugin=diff is not implemented.
http://yellow.ribbon.to/~tuotehhou/index.php?%2BSqlServer%2BT-SQL%E3%81%A7%E3%83%91%E3%82%B9%E3%81%AE%E6%96%87%E5%AD%97%E5%88%97%E3%82%92%E5%88%86%E6%9E%90
plugin=diff is not implemented.