- 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

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

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

GCC: bring back experimental support for amdfam10/barcelona CPUs.

Initial support for the AMD amdfam10 chipsets has been available in the
gcc43 branch under GPLv2. AMD and some linux distributions (OpenSUSE) did
a backport of the amdfam10 support and made it available.

This is a revised subset of the support initially brought in in r236962
and later reverted. The collateral efects seem to have disappeared but
it is still recommended to set the CPUTYPE with caution.

Reviewed by: jkim (ages ago)
MFC after: 3 weeks