- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r256777-256779,256788:
Add driver for POWER hypervisor interpartition ethernet.

Approved by: re (glebius)

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

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

Merge in support for PAPR-compliant (Power Architecture Platform
Requirements) systems from the projects/pseries branch. This in principle
includes all IBM POWER hardware released in the last 15 years with the
exception of POWER3-based systems when run in 64-bit mode. The main
development target, however, has been the PAPR logical partition support
that is the default target in KVM on POWER and QEMU -- mileage may vary
on actual hardware at present. Much of the heavy lifting here was done
by Andreas Tobler.

Approved by: re (kib)