Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove the advertising clause from UCB copyrighted files in usr.bin. This
is in accordance with the information provided at
ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change

Also add $FreeBSD$ to a few files to keep svn happy.

Discussed with: imp, rwatson

Fix markup nits, add the EXIT STATUS section.

Expand *n't contractions.

A space between switch and open-paren. Don't explicitly cast the value
returned by getopt(3) to 'char' in a switch.

ANSI, __FBSDID()

Use `The .Nm utility'

remove __P

Remove WARNS?=2 and -Wall. WARNS?=2 is going to be the default.

Style improvements recommended by Bruce as a follow up to some
of the recent WARNS commits. The idea is:

1) FreeBSD id tags should follow vendor tags.
2) Vendor tags should not be compiled (though copyrights probably should).
3) There should be no blank line between including cdefs and __FBSDIF.

Warns cleanup - don't declare ttyname(). Add FreeBSD ID to Makefile.

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

$Id$ -> $FreeBSD$

Add usage().

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

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.

[HISTORY] command appeared in Version 1 AT&T UNIX
Obtained from: A Quarter Century of UNIX, Peter H. Salus, page 41

This commit was generated by cvs2svn to compensate for changes in r1590,
which included commits to RCS files with non-trunk default branches.