Add irc-message event

[zoffixznet]

The event will be emitted for all PRIVMSG and NOTICE messages and will be go after irc-privmsg/irc-notice have been emitted.

This will allow for use of trigger-based responses and avoid stuff like this:

method irc-privmsg-channel ($e) { self.handle: $e.text; }
method irc-to-me           ($e) { self.handle: $e.text; }