Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

beforeinstall -> SCRIPTS.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

$Id$ -> $FreeBSD$

This commit was generated by cvs2svn to compensate for changes in r28112,
which included commits to RCS files with non-trunk default branches.

Initial import of periodic executable control program.