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

Garbage collect argc/argv and bump WARNS to 6

MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

Add unix_sorflush, a regression test for the following scenario:

- Process (a) is blocked in read on a socket waiting on data.
- Process (b) is blocked in shutdown() on a socket waiting on (a).
- Process (c) delivers a signal to (b) interrupting its wait.

When the signal is delivered, the kernel panics as sblock() fails in
sorflush(). Even if it didn't panic, shutdown() would block potentially
indefinitely waiting for recv() to succeeded. Fixes to follow.

Reported by: Jos Backus <jos at catnook dot com>