Log Message:
Update mimedefang to version 2.24

Changes in 2.24:
This release includes "watch-mimedefang", a graphical monitoring tool \ 
[not enabled].
It does stricter checks on functions which only make sense in the context of a
message. Global variables are cleared between messages so that extraneous values
don't stick around. There are important fixes for Solaris and possibly other
non-Linux machines.

Changes in 2.23:
A bug which could crash mimedefang-multiplexor under conditions of extreme load
has been fixed. An attacker with sufficient bandwidth may be able to exploit the
bug to mount a denial-of-service attack.

Changes in 2.22:
Support has been added for clamd, the daemonized version of Clam AntiVirus. A new
variable $MaxMIMEParts lets you reject overly complex MIME messages which could
otherwise result in a DoS. A new action_delete_all_headers routine has been added
which deletes all instance of a given header. Many little bugs were fixed and
portability was improved.