Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

META MODE: These need object directories to handle staging.

Sponsored by: EMC / Isilon Storage Division

Follow-up to r255036; remove beforeinstall directives from bsdconfig(8)
Makefile's, fixing concurrent installworld (`make -j17 installworld').

Thanks to: delphij, emaste
Reviewed by: delphij
MFC after: 3 days
X-MFC-to: stable/10, stable/9

Implement GEOM based media device classification. You'll notice a few
different things from this commit:
+ More devices. Devices that were previously ignored are now present.
+ Faster device scanning. "There is no try, only Do" -- f_device_try()
is no longer the basis of device scanning as GEOM provides [nearly]
all devices (doesn't provide network devices).
+ More information available as non-root. Usually you have to be root
to do things like taste filesystems, and that limits the amount of
information available to non-root users; with GEOM, we see all even
running unprivileged as the brunt of information (except for so-
called ``dangerously dedicated'' file systems) is represented by the
`kern.geom.confxml' sysctl(8) MIB.
NB: Only really useful for external scripts that use the API and run as
non-root; where this code is used in bsdconfig(8) and bsdinstall(8)
you are running as root so can detect even ``dangerously dedicated''
file systems that are not present in GEOM; e.g., no PART class for
a DOS filesystem written directly to disk without partition table).
+ No more use of legacy tools such as diskinfo(8) to get disk capacity
or fdisk(8) to see partitions.

MFC after: 1 week

Add keymap.subr for presenting custom keymap dialogs (with X11 support).

Approved by: re (glebius)

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)