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

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

Spelling fixes for usr.sbin/

- 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

Various fixes and improvements:
- fix harmless compiler's warnings (unused variables and missed prototype);
- before refusing to delete package because "there are packages installed
that require this package" check that packages in question is actually
installed;
- add new `-r' option to pkg_delete(8), which instructs it to delete not only
packages specified at command line, but all packages that depend on
specified packages as well.

MFC after: 2 weeks

- Merge recently added into pkg_info(1) regex/glob matching functionality into
pkg_delete(1) as well;
- add a new `-a' option for pkg_delete(1) to delete all installed packages;
- add a new `-i' option for pkg_delete(1) to request simple rm(1)-like
interactive confirmation before attempting to delete each package.

Silently approved by: jkh, -ports

$Id$ -> $FreeBSD$

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Many of John T. Kohl's patches from NetBSD. Thanks, John!
Submitted by: jkohl

This commit was generated by cvs2svn to compensate for changes in r327,
which included commits to RCS files with non-trunk default branches.

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