- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

Regenerate after r220401. It turns out makeman is clever about implied
flags, so remove that part from WITHOUT_CXX again.

This is only partially regenerated, as the entries for FDT and GPIO seem to
have switched their default state, too.

Complete WITHOUT_CXX support. It implies WITHOUT_GROFF and
WITHOUT_CLANG.

Don't build clang bootstrap/build-tools depending on this flag. We also
keep gperf, devd and libstdc++ around to prevent foot-shooting and to
make this a two-way street.

Prepare to autogenerate the src.conf(5) manpage.