[v1.1.1] New stackoverflow plugin & general bug fixes.
- New stackoverflow plugin to search Stack Overflow for the replied-to message, or the given search query
- anticrypto now clears up after itself
- Join CAPTCHAs now handle auto-kicks in a different way, by expiring keys and checking they're not there, rather than checking to see if the key has existed for longer than 5 minutes
- Removed some stray debug code