sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Perform cleanups to the TTY headers:

- Properly sort the ioctls in ioctl_compat.h. Also perform some
whitespace fixes.
- Properly comment all the unused/compat ioctls in ttycom.h.

Add support for old TTY ioctls to kdump.

At first I allowed ioctl_compat.h to be included, but it just returned
an empty file. I had to do this, to keep kdump happy. I really want to
raise a compiler error when including this header, so now it will just
throw an error if you don't set COMPAT_43TTY.

Burn TTY ioctl bridges in compat layers.

I really don't want any pieces of code to include ioctl_compat.h, so let
the ibcs2 and svr4 compat leave sgtty alone. If they want to support
sgtty, they should emulate it on top of termios, not sgtty.

The code has been marked with BURN_BRIDGES for a long time. ibcs2 and
svr4 are not really popular pieces of code anyway.

- Import the HEAD csup code which is the basis for the cvsmode work.

Remove OTTYDISC, NETLDISC and NTTYDISC definitions.

When I ported most applications away from <sgtty.h>, I noticed none of
them were actually using these definitions. I kept them in place,
because I didn't want to touch tools like pstat(8) and stty(1).

In preparation for the MPSAFE TTY layer, remove these definitions. This
doesn't have any impact with respect to binary compatibility (see
tty_conf.c).

We couldn now add an #error to <sys/ioctl_compat.h> when included
outside the kernel. Unfortunately, kdump's mkioctls includes this file
unconditionally.

Approved by: philip (mentor)

Turn sgtty into a binary-only compatibility interface.

sgtty was the original interface to configure terminal attributes on my
UNIX-like operating systems. It has been deprecated by the POSIX termios
interface, which is implemented in almost any modern system.

An advantage of turning this into a binary compatibility interface, is
that we can now eventually remove the COMPAT_43TTY switch from kernel
configurations. This removes many ioctl()'s from the TTY layer.

While there, increase the __FreeBSD_version, which may be useful for the
people working on the Ports tree.

Reviewed by: kib
Approved by: philip (mentor)

Increase the verbosity of the warning given when this file is used as
part of the old tty system - helping the user to know how to transition to
the new tty api.

Approved by: mlaier (Mentor)

PR: kern/110667

Move the old BSD4.3 tty compatibility from (!BURN_BRIDGES && COMPAT_43)
to COMPAT_43TTY.

Add COMPAT_43TTY to NOTES and */conf/GENERIC

Compile tty_compat.c only under the new option.

Spit out
#warning "Old BSD tty API used, please upgrade."
if ioctl_compat.h gets #included from userland.

/* -> /*- for license, minor formatting changes

Put the pre FreeBSD-2.x tty compat code under BURN_BRIDGES.

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core

$Id$ -> $FreeBSD$

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

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.

Added $Id$

BSD 4.4 Lite Kernel Sources