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

Make tohex() work as expected.

Fix a typo.

PR: 205722

Create libstand version of uuid_from_string and uuid_to_string. The
normal libc versions of these functions use asprintf and sscanf, both
of which aren't available in the libstand world. It's easier to
rewrite these than to try to claw those functions into libstand.
Also include uuid_create_nil, since it's safe to include. These were
written from scratch, except for bits of comments that I got from the
libc version, which are acknowledged in the source.

Differential Revision: https://reviews.freebsd.org/D4540