Customizing amavis.conf

[Robert Moskowitz]

The 'standard' practice for instructions for customizing amavis.conf 
have been to edit the file.

But after working on the roundcubemail php files, I think I have learned 
a 'better' way?

amavis.conf is processed sequentially and is all about setting a bunch 
of variables.  Thus I *SHOULD* be able to just append my changes at the 
end instead of figuring out all the places to change.

One caveat with amavis.conf that I have not seen in other .conf files is 
the last line:

1;  # insure a defined return value

Again, nothing says this cannot occur more than once, so I *SHOULD* be 
able to end my variable settings append with that line.

This would make for a cleaner record of changes made, rather than 
remembering all the places that were changed.  Also cleaner instructions 
in a howto.

thanks!