You dont necessarily need "integration" to achieve this. You can always put a file under version control.

I've stole some links from https://github.com/gioele/pw to show that there are downsides to the separate files approach:

http://nms.csail.mit.edu/projects/ssh/

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-2666