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

MFV r248590,248594:
Update libarchive to 3.1.2

Some of new features:
- support for lrzip and grzip compression
- support for writing tar v7 format
- b64encode and uuencode filters
- support for __MACOSX directory in Zip archives
- support for lzop compresion (external utility)

Update libarchive's vendor dist to version 3.1.2 from release branch.

Git branch: release
Git commit: 19f23e191f9d3e1dd2a518735046100419965804

Obtained from: https://github.com/libarchive/libarchive.git