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.

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

Move the __packed declarations. This makes sizeof(struct llc) 8 again
on the arm. Add an assert to ensure that the size is 8 to prefent others
from falling into this trap (we should have more of these).

Why the construct:

struct foo {
union bar {
struct {
...
} __packed fred;
...
} __packed wilma;
} __packed;

has a different packing than:

struct foo {
union bar {
struct {
...
} fred __packed;
...
} wilma __packed;
} __packed;

is beyond my ability to ferret out of the gcc documentation. Most
likely some subtle binding issue (eg before it says the struct itself
is packed, while after it means that the whole struct is packed into
the thing it is in). Pointers to relevant documentation would be
appreciated.

Add hooks into the networking layer to support if_bridge. This changes struct
ifnet so a buildworld is necessary.

Approved by: mlaier (mentor)
Obtained from: NetBSD

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

Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

s/__attribute__((__packed__))/__packed/g

Sync with NetBSD.

$Id$ -> $FreeBSD$

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.

Fix a bunch of spelling errors in the comment fields of
a bunch of system include files.

Make idempotent.

Submitted by: Paul

Added $Id$

BSD 4.4 Lite Kernel Sources