active formats, ie. changing theme changes scrollback.
It's still a bit buggy (can crash) with multiline formats, need to fix
it as soon as I figure out where the problem is..
git-svn-id: http://svn.irssi.org/repos/irssi/trunk@852 dbcabf3a-b0e7-0310-adc4-f8d773084564
later if you used /format it would change the old lines too. However
the actual line changing doesn't work yet :)
git-svn-id: http://svn.irssi.org/repos/irssi/trunk@836 dbcabf3a-b0e7-0310-adc4-f8d773084564
