sleep: Overhaul.

Program:

* Add a dummy getopt(3) loop to handle `--`.
* Move interval parsing out into a separate function.
* Print a diagnostic for every invalid interval.
* Check for NaN and infinity.
* Improve bounds checks.

Manual page:

* Miscellaneous markup fixes.
* Reword DESCRIPTION section.
* Move text about GNU compatibility to STANDARDS section.
* Convert examples from csh to sh.

Sponsored by: Klara, Inc.
Reviewed by: kevans
Differential Revision: https://reviews.freebsd.org/D44471

bin: 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

Remove $FreeBSD$: one-line nroff pattern

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

sleep.1: Fix mdoc style

Fixes: be038c3afcae bin/sleep: add support for multiple delay values
MFC after: 1 week

bin/sleep: document more non-standard features

Add support of other time units than seconds to the IMPLEMENTATION
NOTES section of the man page.

MFC after: 1 week

bin/sleep: add support for multiple delay values

The sleep time is calculated as the sum of all arguments passed.

This makes the FreeBSD version of sleep functionally compatible with
the version in GNU coreutils.

MFC after: 1 week

bin/sleep: add support for units other than seconds

The coreutils version of this command accepts a unit designation of s,
m, h, or d (for seconds, minutes, hours, days) immediately following
the number of (fractional) units to delay.

The submitted patch has been modified in one detail: the test meant to
detect the presence of the unit modified was not specific (!= 1) and
would have accepted a non-numeric initial element or extra characters
following the union. The committed version accepts only the number
immediately followed by one of the defined unit designators and no
further characters.

PR: 264162
MFC after: 1 week

Soften caveat about fractional seconds for sleep(1)

Support for fractional seconds has become much more widespread since
this text was originally written.

Reported by: Mark Eichin
Reviewed by: gbe, jilles
Differential Revision: https://reviews.freebsd.org/D26208

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.

Document the new argument parser for sleep(1) and SIGINFO behaviour.
Remove higlight for the unportability notice.

MFC after: 3 weeks

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.

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

Add the new standard EXIT STATUS section where appropriate.
Sort standard sections in the (documented) preferred order.

/*- or .\"- or #- to begin license clauses.

Remove clause 3 from the UCB licenses.

OK'ed by: imp, core

Sort sections, use Ex macro in Diagnostics section, point out that the first
example only works with csh(1).

Add History section. sleep appeared in v4.

mdoc(7) police:

Avoid using parenthesis enclosure macros (.Pq and .Po/.Pc) with plain text.
Not only this slows down the mdoc(7) processing significantly, but it also
has an undesired (in this case) effect of disabling hyphenation within the
entire enclosed block.

Prepare for mdoc(7)NG.

Remove more single-space hard sentence breaks.

Restore reference to sleep(3).

Let sleep(1) handle fractions of a second (up to nanosecond).

This is a conservative change. It does the same thing in weird
cases like the old one. For example, 'sleep abcd' still sleeps
for zero seconds. `sleep 10.a' and `sleep 10.05aa' do the best
and not abort (ie: 10.a == 10 seconds, 10.05a == 10.05 seconds).

$Id$ -> $FreeBSD$

Describe proper signals behavior rather than just removing it.
Remove obsoleted reference to alarm(3).

Submitted by: bde

There is no special handling for SIGALRM as
sleep(3) is implemented using nanosleep(2).

Various spelling/formatting changes.

Submitted by: Philippe Charnier <charnier@xp11.frmug.org>

Correct use of .Nm. Add rcsid.

Describe signals behaviour now

Revert $FreeBSD$ to $Id$

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.

Sort cross references.

Cleanup man page and -Wall cleaning.

Added $Id$

BSD 4.4 Lite bin Sources