- 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: xz 5.2.2.

Relnotes: yes

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

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

Remove unneeded WARNS=3 lines.

It seems these two tools can be built properly with WARNS=6, even on
architectures that are stricter about alignment.

Add two public headers missing in r207842
Adjust CFLAGS for lzmainfo, xz, xzdec

Approved by: delphij (mentor)
MFC after: 2 weeks

Import of liblzma, xz, xzdec, lzmainfo from vendor branch
Add support for xz and lzma to lesspipe.sh (xzless, lzless)
Bump __FreeBSD_version

Approved by: delphij (mentor)
MFC after: 2 weeks