[Xymon] Alternate devmon SNMP

[Bruno Manzoni]

Hello,

I created a repo with "devmon" github/bonomani and included all
patches/contrib and resolved all bugs I can. (I try to integrate all
patches, bugs and features from SF) see the REAMDE for details

This is not an official update of current "devmon" but I have
difficulties to have an answer on current sourceforge repo, so I decided
to publish what I have done. (I did not have any answer on my patches
after myn years!?)

As i am working on Centos, there are some specific things for systemd.

I trying also to contact devmon admins to merge this work or part of
it,  so if you have a clue...

If you want to test this work, you should simply take the files in the
"modules" dir and it should work...with your current installation

And of course any suggestions are welcome!

Bruno