- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

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

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

Use DEVMETHOD_END macro defined in sys/bus.h instead of {0, 0} sentinel on device_method_t arrays

Reviewed by: cognet
Approved by: cognet

This isn't functionally identical. In some cases a hint to disable
unit 0 would in fact disable all units.

This reverts r241856

Approved by: cperciva (implicit)

Now that device disabling is generic, remove extraneous code from the
device drivers that used to provide this feature.

Reviewed by: des
Approved by: cperciva
MFC after: 1 week

amdsbwd: update to support SB8xx southbridges

Many thanks to Tino <tinotom@gmail.com> for drawing my attention to
this, for doing a lot of testing and providing great feedback.
Many thanks to AMD for continuing to release public specifications for
their chipsets.

PR: kern/157568
Tested by: Tino <tinotom@gmail.com>
MFC after: 1 week

amdsbwd: fix nonsensical timeout calculations

in case when sub-second interval is being programmed

Found by: clang static analyzer
MFC after: 4 days

amdsbwd: new driver for AMD SB600/SB7xx watchdog timer

The hardware is compliant with WDRT specification, so I originally
considered including generic WDRT watchdog support, but decided
against it, because I couldn't find anyone to the code for me.
WDRT seems to be not very popular.
Besides, generic WDRT porbably requires a slightly different driver
approach.

Reviewed by: des, gavin, rpaulo
MFC after: 3 weeks