PBot now finally supports IRCv3 message tags. The `account-tag`
capability is now enabled for improved NickServ account tracking.
Refactored CAP negotiation. Minor clean-ups in AntiFlood.pm (which ought to
be completely rewritten from the ground-up).
Misc clean-ups and refactoring of various things.
For some reason, various IRC networks do not propagate banlist metadata
such as owner and timestamp when a server rejoins. This causes the
server's banlist entries to contain "set by server" instead of the
original individual who set it and "set on now" instead of when it was
originally set.
This commit modifies PBot's banlist monitoring to only update PBot's
internal banlist metadata when the ban doesn't exist or when the ban is
being updated by an actual individual instead of the server. Now PBot
will remember the original setter and the original timestamp
regardless of whether the IRC server can.
