Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Mark usage function as __dead2 in programs where it does not return

In most cases, usage does not return, so mark them as __dead2. For the
cases where they do return, they have not been marked __dead2.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/735

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

No functional change intended.

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

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

ANSIfy almost all applications that use WARNS=6.

I was considering committing all these patches one by one, but as
discussed with brooks@, there is no need to do this. If we ever
need/want to merge these changes back, it is still possible to do this
per application.

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

Make this WARNS=6 clean by prototyping 'usage'.

Tested by: make universe

Use __FBSDID() to quiet GCC 3.3 warnings.

Include missing header files which define functions for which gcc has
builtins (e.g., exit, strcmp).

Remove the use of a dash in the usage, since this isn't in keeping
with other utilities which offer similar functionality.

This change was discussed with ache, who brought in the ability to
use a dash to represent stdin in comcontrol.

Print options only supported by device, back out printing options separately

Pointed-by: bde

Allow "-" for working with STDIN
Allow printing of each option separately when keyword specified without a
number

$Id$ -> $FreeBSD$

Add rcsid. Remove unused #includes. Use err(3).

Remove excessive argc checking. It was impossible to set `dtrwait' and
and `drainwait' in a single command.

Fight agaist hanging modems: add new drainwait option.
Reviewed by: Bruce

From Bde:
o Removed bidir options.

Modified for work without options COM_BIDIR into kernel.

Add 'dtrwait <n>' option to comcontrol to handle
TIOCM[SG]DTRWAIT ioctl.

Initial import, 0.1 + pk 0.2.4-B1