martin f. krafft <madduck@madduck.net> [Mon, 09 Apr 2012 18:10:56 +0200] rev 504
First version of a CatchallAlias class
I based the CatchallAlias class in catchall.py heavily on the Alias class, but
by copy, not deriving. The two are functionally related, but the
implementations are too different because CatchallAliases have no localpart.