Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Merge the projects/release-pkg branch to head.

This allows packaging the base system with pkg(8), including
but not limited to providing the ability to provide upstream
binary update possibilities for non-tier-1 architectures.

This merge is a requirement of the 11.0-RELEASE, and as such,
thank you to everyone that has tested the project branch.

Documentation in build(7) etc. is still somewhat sparse, but
updates to those parts will follow.

Sponsored by: The FreeBSD Foundation

Convert sbin/ to LIBADD
Reduce overlinking

Use src.opts.mk in preference to bsd.own.mk except where we need stuff
from the latter.

Migrate tools/regression/sbin/ to the new tests layout.

Pretty much all that this change does is shuffles the code around and hooks
it into the regular build. The code of the old tests has not changed.

Remove ancient vnconfig symlink

Submitted by: ak
Approved by: cperciva
MFC after: 1 week

Make mdconfig(8) WARNS=6 clean:

- Constify geom_config_get() name argument.
- Add void keyword for usage().
- Initialize mdunit to NULL.
- Don't call md_prthumanval() at all if length is NULL.

Approved by: trasz (mentor)

Switch the default WARNS level for sbin/ to 6.

Submitted by: Ulrich Spörlein

Make WITHOUT_DYNAMICROOT=foo work again: remember to reference
libbsdxml and libsbuf.

Teach md(4) and mdconfig(8) how to understand XML. Right now there won't be
a problem with listing large number of md(4) devices. Either 'list' or
'query' mode uses XML.

Additionally, new functionality was introduced. It's possible to pass
multiple devices to -u:

# ./mdconfig -l -u md0,md1

Approved by: cognet (mentor)

- Make md(4) 64-bit clean.
After this change it should be possible to use very big md(4) devices.
- Clean up and simplify the code a bit.
- Use humanize_number(3) to print size of md(4) devices.
- Add 't' suffix which stands for terabyte.
- Make '-S' to really work with all types of devices.
- Other minor changes.

Default to WARNS=2.
Binary builds that cannot handle this must explicitly set WARNS=0.

Reviewed by: mike

Constify mdmaybeload(), add a prototype for usage(), and get rid of a
sizeof(int) == sizeof(long) assumption; clamp down with WARNS=2.

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

Set the default manual section for sbin/ to 8.

Make md(4) and mdconfig(8) take over the role of vn(4) and vnconfig(8)
entirely as previously advertised.

md(4) adopted all assets of vn(4) some time back and has proper devfs
support and cloning abilities to boot.

Improve cmdline parsing and messages.

Add a rudimentary man-page. (I'm no mdoc wizard, feel free to attack my
mistakes and blunders)

Preliminary scaffolding for the new integrated vn+md device driver.

I decided to work on the md(4) driver and integrate the vn(4)
functionality into it mainly based on the name being more suitable.
Ideally 'vd' as in "virtual disk" would probably be the most logical
but our sound-master pointed out that this would cause uncontrollable
fits of giggles in the brits. Another complication would the needed
changes to the ramdisk boot/root functionality.

The vn driver will stay around for some time after I complete this
merge for transition reasons, and I'll make it whine to people that
they should migrate to the md(4) driver for some time before it
dies.

The kernel part of the new md(4) driver will be committed after more
testing.