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

MFC r271493,271688-271689,271696,271854,272139-272143:

Import HyperV Key-Value Pair (KVP) driver and daemon code by Microsoft,
many thanks for their continued support of FreeBSD.

While I'm there, also implement a new build knob, WITHOUT_HYPERV to
disable building and installing of the HyperV utilities when necessary.

The HyperV utilities are only built for i386 and amd64 targets.

Approved by: re (gjb)

Properly revert r272128.

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

Revert r272149, which introduces obscure vestiges from the
r272128 reversal.

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

Revert r272128:
Though this passes the buildworld test, this fails during
installworld with:

make[3]: "/releng/scripts-release/chroots/10/i386/release/etc/devd/Makefile"
line 13: Malformed conditional (${MK_HYPERV} != "no")

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

MFC r271493,271688,271689,271696,271854:

Import HyperV Key-Value Pair (KVP) driver and daemon code by Microsoft,
many thanks for their continued support of FreeBSD.

While I'm there, also implement a new build knob, WITHOUT_HYPERV to
disable building and installing of the HyperV utilities when necessary.

The HyperV utilities are only built for i386 and amd64 targets.

Approved by: re (gjb)

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

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

- Trim an unused and bogus Makefile for mount_smbfs.
- Reconnect with some minor modifications, in particular now selsocket()
internals are adapted to use sbintime units after recent'ish calloutng
switch.

Replace sade the extracted piece of sysinstall with sade the extracted
piece of bsdinstall (although this time with a symlink instead of duplicated
source code).

Discussed on: freebsd-geom
MFC after: 3 months

Disconnect non-MPSAFE SMBFS from the build in preparation for dropping
GIANT from VFS. In addition, disconnect also netsmb, which is a base
requirement for SMBFS.

In the while SMBFS regular users can use FUSE interface and smbnetfs
port to work with their SMBFS partitions.

Also, there are ongoing efforts by vendor to support in-kernel smbfs,
so there are good chances that it will get relinked once properly locked.

This is not targeted for MFC.

Disconnect non-MPSAFE NWFS from the build in preparation for dropping
GIANT from VFS. In addition, disconnect also netncp, which is a base
requirement for NWFS.

In the possibility of a future maintenance of the code and later
readd to the FreeBSD base, maybe we should think about a better location
for netncp. I'm not entirely sure the / top location is actually right,
however I will let network people to comment on that more specifically.

This is not targeted for MFC.

Merge from tbemd: use Makefile.arch to control building.

Reviewed by: arch@ (many times, no objection)