Fixing mail/mailman and avoiding breakage this time

[Chris Rees]

Hi all,

I've reverted the problem commit to mailman, but I will push forward with
changing the method for creating users because the state of the port
at the moment is unacceptable (fiddling with base files before install
phase).

Please test the patch below and check that it works -- I've tested it
myself but it appears a very fragile port!

Madpilot, this is mostly your patch, thanks.

Chris

http://people.freebsd.org/~crees/patches/mailman-uids-fix.diff