- 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

Pull in r170135 from upstream clang trunk:

Dont use/link ARCMT, StaticAnalyzer and Rewriter to clang when the user
specifies not to. Dont build ASTMatchers with Rewriter disabled and
StaticAnalyzer when it's disabled.

Without all those three, the clang binary shrinks (x86_64) from ~36MB
to ~32MB (unstripped).

To disable these clang components, and get a smaller clang binary built
and installed, set WITHOUT_CLANG_FULL in src.conf(5). During the
initial stages of buildworld, those extra components are already
disabled automatically, to save some build time.

MFC after: 1 week

Upgrade our copy of llvm/clang to r168974, from upstream's release_32
branch. This is effectively llvm/clang 3.2 RC2; the 3.2 release is
coming soon.

Upgrade our copy of llvm/clang to trunk r154661, in preparation of the
upcoming 3.1 release (expected in a few weeks). Preliminary release
notes can be found at: <http://llvm.org/docs/ReleaseNotes.html>

MFC after: 2 weeks