Remove svn:mergeinfo carried over from stable/9.

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

Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r240090:

Improve file rotation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

1. Attempt to take one bullet out of the foot-shooting gun by silently
ignoring errors when sourcing rc.conf* files. The most common error
occurs when users put a command of some sort into those files.
(ifconfig is a popular choice)

2. Make the file rotation logic simpler by starting one down from
the "top" of the list, rather than at the top.

3. Try to make file rotation more secure by calling unlink(1) on all
new file names before rotating an old file to the new name, rather than
merely calling 'rm -f' on any files that exceed the number of files
to save.

The script mistakenly ignores the entropy_save_sz variable from
rc.conf[.local]. Fix this, and leave the default as 2048.

Update the copyright year to include the present.

Update the assignment of the copyright to be me personally,
instead of "The FreeBSD Project" which is not a legal entity,
and therefore not a proper assignee. My intention remains the
same however, that this code continue to be BSD licensed, and
freely available to anyone that wants it under those terms.

PR: conf/75722
Submitted by: Nicolas Rachinsky <list@rachinsky.de>

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

Mark bits that do not require an object directory as such.

beforeinstall -> SCRIPTS.

Move the process of storing entropy from /dev/random and reseeding with
it at boot time closer to the way we want it to be in the final version.

* Move the default directory to /var/db/entropy
* Run the entropy saving cron job every 11 minutes. This seems
to be a better default, although still bikeshed material.
* Feed /dev/random some cheesy "entropy" from various commands
and files before the disks are mounted. This gives /dev/random
a better chance of running without blocking early.
* Move the reseeding with previously stored entropy to the point
immediately after the disks are mounted.
* Make the harvesting script a little safer in regards to the
possibility of accidentally overwriting something other
than a regular file.

Add a system to save entropy from /dev/random periodically so that
it can be used to reseed at boot time. This will greatly increase
the chances that there will be sufficient entropy available at
boot time to prevent long delays.

For /etc/rc, remove the vmstat and iostat runs from the attempt
to provide some cheesy randomness if the files fail, since
those programs are dynamically linked, and ldd seems to want
some randomness to do its magic.

Guidance and parameters for this project were provided by
Mark Murray, based on the requirements of the Yarrow
algorithm. Some helpful suggestions for implementation
(including the tip about iostat and vmstat) were provided
by Sheldon Hearn. All blame for problems or mistakes is
mine of course.