Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add the Clang specific -Wmissing-variable-declarations to WARNS=6.

This compiler flag enforces that that people either mark variables
static or use an external declarations for the variable, similar to how
-Wmissing-prototypes works for functions.

Due to the fact that Yacc/Lex generate code that cannot trivially be
changed to not warn because of this (lots of yy* variables), add a
NO_WMISSING_VARIABLE_DECLARATIONS that can be used to turn off this
specific compiler warning.

Announced on: toolchain@

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)

Add src.conf option WITH_SHARED_TOOLCHAIN to enable building the
toolchain binaries as dynamically linked. Option is disabled by
default.

Reviewed by: ru (previous version)
MFC after: 2 weeks

Removed ar(1)'s support for compressed archives. This change removes
ar(1)'s dependencies on compressor libraries -lz, -lbz2 and -llzma and
fixes building HEAD on some versions of FreeBSD[78]. Option -j and -z
is now accepted but ignored.

Compressed ar(1) archives are not useful without a ld(1) that can read
them. Also, the current ar(1) compression scheme prevents random
access of archive members and needs to be redesigned anyway.

Submitted by: kientzle (original patch)
Reviewed by: delphij
Discussed on: -current mailing list

Enable liblzma support in libarchive
Adjust dependencies for programs using libarchive
Add xz and linkage against liblzma to rescue system

Approved by: kientzle, delphij (mentor)
MFC after: 2 weeks

Build usr.bin/ with WARNS=6 by default.

Also add some missing $FreeBSD$ to keep svn happy.

Fix build.

Add support for option "-M", which is used to operate ar(1) in a
script mode like the MRI(Microtec Research Inc.) "librarian" program.

Originally this option is provided by Binutils ar(1) to ease the
transition for developers who are used to writing "librarian" scripts.

We added this option to BSD ar(1) because:

1. Further improve the compatibility with Binutils ar(1).
2. There are still a few software using this -M option. (at least one
in our ports collection)

Suggested by: rink & erwin

Make again BSD ar(1) the default system ar(1), now properly handling
source upgrades by falling back to GNU ar(1) as necessary. Option
WITH_BSDAR is gone. Option _WITH_GNUAR to aid in upgrades is *not*
supposed to be set by the user.

Stop bootstrapping BSD ar(1) on the next __FreeBSD_version bump, as
there are no known bugs in it. Bump __FreeBSD_version to anticipate
this and to flag the switch to BSD ar(1), should it be needed for
something.

Input from: obrien, des, kaiw

Clean up created turds.

We build important toolchain statically. So build BSD 'ar' statically
when its replacing GNU 'ar'.

Re-introduce the new BSDLed 'ar' to the build.
It is installed as "bsdar" unless WANT_BSDAR is defined.

Discussed with: kaiw

Fix static linkage.

Import ar(1) front-end. (aka 'BSD' ar)

Reviewed by: jkoshy
Approved by: jkoshy (mentor)
Tested by: erwin (ports build test on pointyhat)
Sponsored by: Google Summer of Code 2007
Reviewed by (earlier version): Jaakko Heinonen <jh[AT]saunalahti.fi>
Tested by (earlier version): Steve Kargl <sgk[AT]troutmask.apl.washington.edu>
Tested by (earlier version): Martin Voros <martin_voros[AT]yahoo.com>
Tested by (earlier version): swell.k[AT]gmail.com
Tested by (earlier version): joel
Tested by (earlier version): Alexey Shuvaev <shuvaev[AT]physik.uni-wuerzburg.de>
Tested by (earlier version): Arjan van Leeuwen <avleeuwen[AT]gmail.com>

Thanks to gabor@ for building ports for it.
Thanks to erwin@ and kris@ for scheduling the ports build test on pointyhat.
And thanks to many others for their feedback.