mailman2->3 update (was: www/trac update and python 2.7 (volunteers, if not drive-by update))

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

> mailman3 is in wip, and I'm not sure why it isn't in pkgsrc proper.  I'm
> also not sure if there are good reasons not to migrate any mailman2
> instances to mailman3.
I haven't looked into it myself, but I have been told that Mailman 3 is 
a completely different program than Mailman 2.