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

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

o style.Makefile(5): WARNS= -> WARNS?=.

Style: NO_MAN doesn't need any value.

Add a regression test to test two variations on the same bug: joining a
multicast group using a raw socket, then removing the interface on which
the group is found, and joining a multicast group using a udp socket,
then removing the interface on which the group is found. An if_disc
interface is used as the interface on which to attach.

NB: A panic currently results from running this regression test, so do
so with caution.

PR: 77665
Reported by: Gavin Atkinson <gavin dot atkinson at ury dot york dot ac dot uk>
Reported by: Brooks Davis <brooks at FreeBSD dot org>