Docbot integration with websearch

Robert has committed the code to integrate the docbot (familiar to users in the #postgresql IRC channel) with the web search. Basically it does a very simple keyword matching against a limited set of keywords, and presents those hits before we show the full-text searches. Try it out for example by searching for lock.

Hopefully this will help out when people search for really ambigous things (like lock in the example) where a full text search can give too many and too unrelated results.

Thanks, Rob, now I didn't have to do that. But I'll steal your fame by blogging about it first.