Simplify dvd package population with pkg-1.3.

Submitted by:	bdrewery
MFC after:	3 days
X-MFC-With:	r271480, r271483
Sponsored by:	The FreeBSD Foundation
Workaround for receiving Voice Calls using the E1750 dongle from
Huawei. It might appear as if the firmware is allocating memory blocks
according to the USB transfer size and if there is initially a lot of
data, like at the answering machine prompt, it simply dies without any
apparent reason. The simple workaround for this is to force a zero
length packet at hardware level after every 512 bytes of data. This
will force the other side to use smaller memory blocks aswell.

MFC after:	1 week
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.

This is a stable/10 candidate for inclusion with 10.1-RELEASE.

Submitted by:	Wei Hu <weh microsoft com>
MFC after:	1 week
Regen.
Add a sysctl to export the EFI memory map along with a handler in the
sysctl(8) binary to format it.

Reviewed by:	emaste
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D771