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

Add support files for using text from the POSIX specification in
FreeBSD manual pages:

- POSIX-copyright contains copyright text to be used in manual pages
which has POSIX text inserted.
- deshallify.sh is a shell script which removes many of the ``shall''
statements from the POSIX text and therefore making the text more
readable.

Real work to make this happen by: nectar, ru