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

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

SPDX: Consider code from Carnegie-Mellon University.

Interesting cases, most likely from CMU Mach sources.

ddb: space/tab fixes.

No functional change.

MFC after: 3 days

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.

Fixed formatting of printing of command tables. WIth the default max
output width of 79, only 6 columns of width 12 each fit, but 7 columns
were printed.

The fix is to pass the width of the next output to db_end_line() and
not assume there that this width is always 1.

Related unfixed bugs:
- 1 character is wasted for a space after the last column
- suppression of trailing spaces used to limit the misformatting, but
seems to have been lost
- in db_examine(), the width of the next output is not know and is
still assumed to be 1.

Simplify the pager support in DDB. Allowing different db commands to
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer). So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt. Also, now that it's easy to do so,
enable paging by default for all ddb commands. Any command that wishes to
honor the quit flag can do so by checking db_pager_quit. Note that the
pager can also be effectively disabled by setting $lines to 0.

Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
terminates early.
- 'show intr' now actually checks the quit flag and terminates early.

Start each of the license/copyright comments with /*-

Remove __P.

$Id$ -> $FreeBSD$

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.

Completed function declarations and/or added prototypes.
Removed `extern' from prototypes.
Sorted prototypes.
Uniformized idempotency ifdefs.

Remove trailing whitespace.

Woops, wrong solution to the problem. Backed out previous fix to ddb.h, and
nuked the db_printf() declaration from db_output.h.
Reviewed by:
Submitted by:
Obtained from:

Makes gcc silent in sys/ddb.

Make the LINT kernel compile with -W -Wreturn-type -Wcomment -Werror, and
add same (sans -Werror) to Makefile for future compilations.

Make all headers idempotent. All incorrect common data moved out of header
files and into a related source file.

Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup. Added $Id$ to files that did not have any version info, etc

Initial import, 0.1 + pk 0.2.4-B1