- 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)

MFC r282115, r282152, r282201
MFV r282150
libgomp: Update to version 4.3.5.
bring initial BSD support from upstream.

This was not meant to be MFC'd at first but the original OMP support
for FreeBSD was in very poor shape. The effect of this change should
be minimal as all ports are already using the version of libgomp that
comes with the gcc ports. The local libgomp is planned to be disabled
for platforms that are not using older gcc by default so this version
of libgomp will not be shipped in tier-1 platform releases.

Discussed with: emaste

MFV r282150
libgomp: Update to version 4.3.5.

This is a partial revert of r282115, to bring the fromal upstream
libgomp from GCC 4.3.5 Release under LGPLv2.1+.

This is only brought to ease the ongoing development of the CPU
affinity support.

This shall not be MFC'd.

Bring updated versions of libcpp and libgomp.

While GCC 4.3 changed license, the library components remained under
LGPLv2.1 all the during all the existence of the branch.
From gcclibs, only libcpp and libgomp have some value for us in the base
gcc 4.2.1: bring updated versions from GCC 4.3.5 as reference as we have
already been including some of the fixes.

These not expected to become part of any FreeBSD release.