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

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

Backout libinstall.a -> libpkg commit.

Discussed with: erwin, brooks, bapt

- Take libinstall.a out of pkg_install and make it a proper shared library.
- Rework the wrapper support to check libpkg version as well as pkg_install
version.
- Add libfetch to _prebuild_libs.
- There are no new features introduced.

Notes: the API is not stable, so basically, do not use libpkg in your
projects for now. Also there's no manpage for libpkg yet, because the API
will change drastically. I repeat, do not use libpkg for now.

The last big commit: let usr.sbin/ use WARNS=6 by default.

Don't put DEBUG to CFLAGS, we have the standard DEBUG_FLAGS for this.

FWIIW, make the `test' target in pkg_install/version actually work.

- pkg_add spawns itself as argv[0] when installing dependent packages, to
enable the use as a port on older systems

- use absolute paths in all calls to external programs, to account for strange
PATH settings

- use INDEX or INDEX-5 depending on FreeBSD version, to enable the use on
FreeBSD 4.x as a port.

- conditionalize all 4.x/5.x differences on __FreeBSD_version, so that the
pkg_install tools can be kept in sync on 4.x and 5.x

- Bump PKG_INSTALL_VERSION

Reviewed by: portmgr (bento run)
MFC after: 4 weeks

- Properly build both crypto and non-crypto versions of the
package management tools.

- Drop redundant dependency of pkg_create(1) and pkg_delete(1)
on crypto libraries now that they do not link with libfetch.

Retire the useless NOSECURE knob.

Approved by: re (scottl)

C replacement for the Perl5 code.

Submitted by: reg

Drop maintainership.

beforeinstall -> SCRIPTS.

Implement a package number comparison routine for pkg_version(1)
that actually conforms to the Porters Handbook.

Add a -t option to pkg_version(1) for doing comparison testing.

Add a script (and make test target) to do some regression tests on
the package number comparison routine, to help debug future revisions.

Submitted by: knu
Procrastination by: bmah

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Now that Bruce Mah is a committer, retire my co-maintainership
of pkg_version.

Correct co-MAINTAINER's e-mail address. I don't know how many
more ways I can screw his address up. Suggestions welcome.

Install man pages in the right place. This is what I get for cheating
and copying a Makefile from another directory over to this one.

PR: docs/15140
Submitted by: Kazuo Horikawa <horikawa@jp.FreeBSD.org>

The author of this is REALLY: Bruce A. Mah <bmah@CS.Sandia.GOV>

Add the author as co-maintainer, a la mergemaster.

Welcome pkg_version into the FreeBSD source tree.

pkg_version (as you may well know) matches the existing packages/ports
installed on your system with the ports INDEX and reports which
ports differ from the current INDEX.

Submitted by: Bruce A. Mah <CA.Sandia.GOV>
Reviewed by: ports