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

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

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

Approved by: re (implicit)

Fix typo

Spotted by: juli

Release the evil twin of nanobsd.sh: sysbuild.sh

quoth the README:

I have been running -current on my laptop since before FreeBSD 2.0 was
released and along the way developed this little trick to making the
task easier.

sysbuild.sh is a way to build a new FreeBSD system on a computer from
a specification, while leaving the current installation intact.

sysbuild.sh assume you have two partitions that can hold your rootfs
and can be booted, and roughly speaking, all it does is build a new
system into the one you don't use, from the one you do use.

A partition named /freebsd is assumed to be part of your layout, and
that is where the sources and ports will be found.

If you know how nanobsd works, you will find a lot of similarity.