change control on FreeBSD servers

[Rogelio Bastardo]

I'm looking for some sort of change control  solution. On several
Cacti/Nagios servers, I would like to take a snapshot of what I did, back it
up, and if something changes, run something that shows me what files /
permissions were changed since I last worked on the server.

If it were just me, then I would just make copies of the files.  But since
there are other people in there doing all sorts of weird configs, I want to
make sure that I document what they did since I last logged in.

Any suggestions would be greatly appreciated.