IRC conversation detection doesn't detect msgs addressing multiple people

[broder@mit.edu]

narrowing on an IRC message where one person addresses another results in narrowing to their "conversation". e.g. M-N on this message:

-> freenode / #ubuntu-devel / pitti  22:59  (pitti!~pitti@ubuntu/member/pitti)
       GrueMaster: that kernel needs a reupload now (and will presumably get
       further updates), I'm afraid

changes my view to "irc-freenode-channel-#ubuntu-devel-pitti-GrueMaster", and just shows messages from those two users.

It's also somewhat common to address multiple people in a message, though. For instance,

   freenode / #ubuntu-devel / pitti  23:08  (pitti!~pitti@ubuntu/member/pitti)
       SpamapS, james_w: hm, your new WI tracker change makes it crash now

or

   freenode / #ubuntu-devel / GrueMaster  15:36  (GrueMaster!~Grue@076-076-148-180
       pitti: sconklin:  I have tested linux-image-2.6.35-24-omap for bug 673509
       and it passed.  I have updated the bug accordingly.  Please see that this
       gets into -updates so I don't have to test it again, thanks.

(the former being much more common, I think) and BarnOwl's smartnarrow doesn't currently detect those.

I have no idea where you draw the line between a colon in the middle of a sentence, and a message addressing multiple people, but I'm sure there's something reasonably clever that can be done.