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

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

ddb: Remove SOFTWARE_SSTEP support

It was needed for mips only, and only kinda sorta worked for mips. It
can be brought back if we grow another architecture that need it.

Sponsored by: Netflix

SPDX: Consider code from Carnegie-Mellon University.

Interesting cases, most likely from CMU Mach sources.

ddb: Minor style cleanups.

#define should be followed by tab.

MFC after: 1 week

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.

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

Revert previous and move the prototype for db_alt_break to ddb.h.

Requested by: bde (I think)

- Add a function db_alt_break which recognizes the character sequence used to
implement ALT_BREAK_TO_DEBUGGER. The caller provides a pointer to a state
variable to allow different state to be maintained for separate instances of
a device.
- Use struct vm_map * instead of vm_map_t in db_break.h to avoid its users
needing to include vm headers.

Requested by: njl

Remove __P.

Fill out some gaps in ia64 DDB support. This involves generalising DDB's
breakpoint handling slightly to cope with the fact that ia64 instructions
are not located on byte boundaries.

$Id$ -> $FreeBSD$

Fixed missing ifdefs and disordering in previous commit.

This commit fixes various 64bit portability problems required for
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.

The prototype FreeBSD/alpha machdep will follow in a couple of days
time.

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.

Reduced and cleaned up #includes.

Untangled the vm.h include file spaghetti.

Staticized and '#ifdef notused' stuff we don't use.

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

Remove trailing whitespace.

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