Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

Simply things so that "#REQUIRE: FILESYSTEMS" means the file
systems are fully "ready to go".

'FILESYSTEMS' states: "This is a dummy dependency, for services which
require file systems to be mounted before starting." However, we have
'var' which is was run after 'FILESYSTEMS' and can mount /var if it
already isn't mounted. Furthermore, several scripts cannot use /var
until 'cleanvar' has done its thing. Thus "FILESYSTEMS" hasn't really
meant all critical file systems are fully usable.

Prepare for the removal of set_rcvar() by changing the rcvar=
assignments to the literal values it would have returned.

The concept of set_rcvar() was nice in theory, but the forks
it creates are a drag on the startup process, which is especially
noticeable on slower systems, such as embedded ones.

During the discussion on freebsd-rc@ a preference was expressed for
using ${name}_enable instead of the literal values. However the
code portability concept doesn't really apply since there are so
many other places where the literal name has to be searched for
and replaced. Also, using the literal value is also a tiny bit
faster than dereferencing the variables, and every little bit helps.

Add the shutdown KEYWORD to those scripts that start persistent services
to allow them to do a "clean" shutdown.

I purposely avoided making changes to network-related stuff since the
system shutting down is pretty conclusive, and there may be complicated
dependencies on the network that I would rather not try to unravel.

I also skipped kerberos-related stuff for the reasons above, and
because I have no way to test it.

As previously discussed, add the svn:executable property to all scripts

Add an rc.d script for stand-alone ftpd.

Document the script's controls on the rc.conf(5)
manpage and touch its Dd.

PR: conf/90893
MFC after: 5 days