Redmine

A common bot that seems to crawl redmine is:

"Sogou web spider/4.0(+http://www.sogou.com/docs/help/webmasters.htm#07)"

but it is not listed as one of the known bots in bots_filter.rb

Actually, there are quite a large number of other bots that aren't listed. It might be good to add a much larger list from the internet, or be more smart about adding them dynamically.