Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

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

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Convert to usr.bin/ to LIBADD
Reduce overlinking

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