Spam filtering

Hello GHCers, As you may have noticed, the GHC Trac instance is currently being hit with a significant amount of spam traffic recently. I believe I've cleared up most of the garbage and the filter configuration has been tightened so that future spam attacks will be easier to quell. Of course, this tightening means that there is a greater chance of false positives. If you do find that your ticket comments or Wiki edits are being rejected by the spam filter, please notify either Austin or me so that we can train the filter on your example. Cheers, - Ben