Revert 184781, 184804, and 184832 (automatic installation of files

Revert 184781, 184804, and 184832 (automatic installation of files
that differ only by VCS Id) for the following reasons:
1. It was added without my consent, review, or even a heads up
2. It is something that I've repeatedly said I do not want, and certainly
do not want as the default
3. It is poorly implemented (much too complex, produces false positives
e.g., /etc/mail/helpfile)

Given that this is a situation that comes up very infrequently (usually
only for a major version upgrade) and can usually be handled simply
enough on a one-off basis, I will once again point out that I think
this is a Bad Idea. I would be willing to consider a better implementation
as an option that is off by default.