[Exim] scanexi plugin

Hi

I needed a dlopen plugin to use something like exiscan with
the experimental Debian exim4 packages. So I modified exiscan.
http://w1.231.telia.com/~u23107873/scanexi.html

First version, works for me.
Many options and features from exiscan still missing.
Requires Exim 4.14 and Spamassassin >=2.50.
Only included Clamav as antivirus scanner for now.
Made it possible to save rejected messages to file.

Thanks everyone that made this possible.

--
Johan Thelmén
Falun Sweden