Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFH r226119: Mention tdsignal(9)

Approved by: des (mentor)

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

The NetBSD Foundation has granted permission to remove clause 3 and 4 from
their software.

Obtained from: NetBSD

Cross-reference signal(9).

mdoc(7) police: Use the new .In macro for #include statements.

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.

Remove single-space hard sentence breaks. These degrade the quality
of the typeset output, tend to make diffs harder to read and provide
bad examples for new-comers to mdoc.

Place #include's and $NetBSD$ tag to appropriate places.

$Id$ -> $FreeBSD$

Add $Id$, to make it simpler for members of the translation teams to
track.

The $Id$ line is normally at the bottom of the main comment block in the
man page, separated from the rest of the manpage by an empty comment,
like so;

.\" $Id$
.\"

If the immediately preceding comment is a @(#) format ID marker than the
the $Id$ will line up underneath it with no intervening blank lines.
Otherwise, an additional blank line is inserted.

Approved by: bde

Cleaned up synopsis:
- don't quote function names, since quoting them is unnecessary and
unusual and confuses my synopsis checker.
- include <sys/types.h> instead of <sys/param.h>. It is normal to
(have to) include <sys/param.h> instead of <sys/types.h>, but it
is more useful for man pages to document minimal prerequisites.

Fixed missing #includes in synopsis.

Add psignal(9).

Obtained from: NetBSD