[Mimedefang] Simplified single purpose mimedefang-filter

[reader at newsguy.com]

Running gentoo linux
sendmail 8.13.6

Just getting started with mimedefang and what brought me to it was
something simpler than complex defanging.

I'm on a single user machine and want to debug my mail setup.  Certain
mail leaves but never appears at its destination.  It is not being
rejected at my local MTA level  nor my ISP smart host.

I don't have any say on ISP smart host so:

I want to see *EXACTLY* what this mail contains as it leaves my mta.
I want a copy of my test mails dropped somewhere just as they appear
going to smarthost hub.

I've done this with a sort of complicated procmail setup and rules in
sendmail.cf long ago but have lost my notes about it and kind of doubt
it would work the same with moden sendmail.

How can I just ignore all the sub funcs in mimedefang-filter or make
them return immediately and get on to the `fiter_end' function where
I can hopefully insert some simple code to create and deposit a copy.

My perl is way too shakey to know how to do that withoug wreaking
major havic.