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

MFC r264840: Implement GEOM based media device classification.

MFC revisions 256321-256323,256331,256333,256335,256343:
Bring in a new zfsboot auto script for performing automatic setup of a boot
pool (optionally encrypted) with many other options, validations, features.
Originally submitted by Allan Jude; modified in collaboration.

MFC revisions 256325,256330,256345:
Rewrite the keymap selection menu to display keymaps and provide a test
mechanism. Test mechanism originally submitted by Warren Block; modified.

MFC r256347:
Prominently display "Wireless" for each wireless network interface. Part
of PR bin/161547; submitted by Warren Block; slightly modified.

MFC r256348:
Remove the dumpdev configuration dialog, merge it into the regular
services configuration and enable it by default. Originally submitted by
Allan Jude; slightly modified.

PR: bin/161547
Submitted by: Allan Jude, Warren Block <wblock@wonkity.com>
In collaboration with: Allan Jude <freebsd@allanjude.com>
Approved by: re (glebius)

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

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

Commit first portion of package module -- this includes the ability to view
categories, view packages, mark packages for installation, de-installation,
or re-installation, calculate and track dependencies, as well as ability to
review selections.

Still to come is the actual processing of selections (performing the
various actions associated with the user's selections, such as installing
dependencies first, then selections, etc.).

Import media selection/preparation framework (sysinstall inspired). Makes
accessing files from various types of media nice and abstracted away from
the wet-work involved in preparing, validating, and initializing those
types of media. This will be used for the package management system module
and other modules that need access to files and want to allow the user to
decide where those files come from (either in a scripted fashion, prompted
fashion, or any combination thereof).

Heavily inspired by sysinstall and even uses the same reserved words so
that scripts are portable. Coded over months, tested continuously through-
out, and reviewed several times.

Some notes about the changes:
- Move network-setting acquisition/validation routines to media/tcpip.subr
- The options screen from sysinstall has been converted to a dialog menu
- The "UFS" media choice is renamed to "Directory" to reflect how sysinstall
treats the choice and a new [true] "UFS" media choice has been added that
acts on real UFS partitions (such as external disks with disklabels).
- Many more help files have been resurrected from sysinstall (I noticed that
some of the content seems a bit dated; I gave them a once-over but they
could really use an update).
- A total of 10 media choices are presented (via mediaGetType) including:
CD/DVD, FTP, FTP Passive, HTTP Proxy, Directory, NFS, DOS, UFS, Floppy, USB
- Novel struct/device management layer for managing the issue of passing
more information than can comfortably fit in an argument list.

Add support for scripting (sysinstall style).

Reviewed by: jilles

Move major includes into /usr/share/bsdconfig for easy external access.

Reviewed by: adrian (co-mentor)
Approved by: adrian (co-mentor)