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 c89(1) invoke /usr/bin/cc with argv[0] also set to /usr/bin/cc,
similar to what c99(1) does, to prevent "c89: illegal option -- 1"
messages, when clang is /usr/bin/cc.

Reported by: tijl
MFC after: 3 days

Revert most part of 200420 as requested, as more review and polish is
needed.

Remove unneeded header includes from usr.bin/ except contributed code.

Tested with: make universe

Sync program's usage() with manpage's SYNOPSIS.

Style improvements recommended by Bruce as a follow up to some
of the recent WARNS commits. The idea is:

1) FreeBSD id tags should follow vendor tags.
2) Vendor tags should not be compiled (though copyrights probably should).
3) There should be no blank line between including cdefs and __FBSDIF.

Use __FBSDID().

WARNS=2 fixup.

Here comes the forgotten C source, oopsy.
Turned the shell script into a binary fixing several minor buglets.
Mention _POSIX_SOURCE feature test macro in man page.
PR: bin/19337
Submitted by: schweikh
Reviewed by: joerg, bde
MFC after: 2 weeks