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

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

MFC r239829:
Follow r239818 and remove no more relevant vslock() ENOMEM error.

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

Remove the BUGS entry for vslock(9) not actually holding user memory in place.

Update "documentation date" fields.

Document exactly how vslock(9) is broken.

Assorted markup, spelling, and grammar fixes.

Change len pararmeter from u_int to size_t.

Document vslock() return values.

use 'void *' instead of 'caddr_t' for useracc, kernacc, vslock and vsunlock.

Update function definitions and required include files to reflect
the current state of the system.

Approved by: alfred

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

mdoc(7) police: removed HISTORY info from the .Os call.

mdoc(7) police: use canonical form of .Dd macro.

Fixed bitrot in synopsis (the third arg of vsunlock went away).

$Id$ -> $FreeBSD$

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

Fixed #include and/or prototype bugs in synopsis.

Add vslock(9) to document the vslock() and vsunlock() kernel functions.

Obtained from: NetBSD