Fix bot's handling of WHO replies on connect:

Some IRCds always output the servername on a WHOX query even if it
wasn't asked for. Let's ask for it now and just ignore the response. The
order of parameters in WHOX is now in the order they are returned, to
make life easier.

Also tidy up the generator a tad; if we aren't using things we're
computing then there's no need to compute it at all :)