Man pages for O_CLOFORK implementation

These are Ricardo Branco's man page updates for affected functions
using O_CLOFORK (and associated variants) for NetBSD (with
a few minor changes and additions by me).

branches: 1.47.2;
execve(2): brush up markup

execve.2: fix typo in markup

Sort errors; remove two more duplicates.

merge the two E2BIG entries (wiz)

Add missing word, add comma in enumeration.

documentation for fexecve(2)

branches: 1.41.10;
file system police.

branches: 1.40.36;
Consistently use `.Brq Dv XXX' across syscalls man pages, for NAME_MAX
and PATH_MAX.

Sort errors.

Remove/convert physical markup.

branches: 1.37.12;
doecument that we now can return eagain.

branches: 1.36.4;
ENOENT is also returned when the script interpreter does not exist.

branches: 1.35.10;
Change HISTORY. It traces execve only back to 4.2BSD, and it is a
touch older than that. (Surprisingly, though, it doesn't appear to
have been in v6.)

cross reference script(7)

\- is a minus, not -.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22280, verified by myself.

Use
.In header.h
instead of
.Fd #include \*[Lt]header.h\*[Gt]
Much easier to read and write, and supported by groff for ages.
Okayed by ross.

Use "its" instead of "it's" where appropriate.
From Soren Jacobsen in PR 20730.

Merge the nathanw_sa branch.

New sentence, new line.

Remove some \f* cruft.

New sentence, new line. From Robert Elz.

Revise wording to say that setting the argument vector is not mandatory.

>xs@kittenz.org:
>susv3 agrees with this, since in the rationale, susv3 states the
>requirement of argc >= 1 was removed recently following iso c. it
>is now only a "should."

bump .Dd .

document a hack about setuid programs and fd 0, 1 and 2.
from OpenBSD.

Generate <>& symbolically. I'm avoiding .../dist/... directories for now.

Sort sections, sort SEE ALSO, punctuation and miscellanous fixes.

Boring whitespace fixes.

branches: 1.19.2;
Add text that says that an interpreter cannot itself be an interpreter
file. Inspired by Solaris manpage and the current NetBSD implementation
as observed with the scotty package and attempts to use the earlier shell
wrapper as an interpreter.

Merge duplicate mentions of EPERM, EACCESS, ... into one entry
(where applicable).

branches: 1.17.2;
ARG_MAX is bumped from 20KB to 256KB since Jan 16 1994 (revision 1.7 of <sys/syslimits.h>). i.e. before NetBSD-1.0 release.
pointed out by NAKAJIMA Yoshihiro and Tanaka Akira on fj.os.bsd.netbsd newsgroup.

Add a LIBRARY section to system call manual pages. While it's clear that the
libraries contain stubs only (with minor exceptions a la pipe(2)), the purpose
of this section is to provide linkage information.

branches: 1.15.6;
Last of the .Os cleanups. .Os is defined in the tmac.doc-common file,
so we shouldn't override it with versions in the manpages. Wheee!

first pass at fixing up capitalization of function names and
arguments; ensure that each is correct with respect to the
implementation, rather than being correct as per english.

merge lite-2

Add missing `STANDARDS' compliance statements. As we #define _POSIX_VERSION
to 199009L, bump existing statements to 1003.1-1990.

xref _exit(2) or exit(3) instead of exit(2)

xref sigprocmask(2), not obsolete sigsetmask(2).

merge with lite, keeping most local changes. clean up Ids

either change or update references to sigvec(), as appropriate

branches: 1.7.2;
Remove description of EINVAL, "The pathname contains a character with the
high-order bit set", as this error is obsolete.

Eventually we may want to add code to some of the "optional" filesystems
(msdosfs, etc.) that checks for illegal characters. At that time it would
be appropriate to reintroduce this error with appropriate text. Perhaps
"The pathname contains a character that is not valid for filesystem type".

Use symbolic names {NAME_MAX} & {PATH_MAX} instead of 255 and 1023 in
description of ENAMETOOLONG error.

Use "Er" for argument to -width in the lists in the ERROR sections --- so
the formatting is consistant.

Clean up manpages:
Use .Fn rather than .Nm macro in HISTORY and STANDARDS sections.
Use .At and .St macros instead of spelling out "Version 6 UNIX",
"IEEE 1003.1-1988 (POSIX)", etc.

fixes from Garrett A. Wollman <wollman@emba.uvm.edu>:
note that EACCES is returned if program file is on an FS mounted
MNT_NOEXEC. also fix missing close-paren.

Add RCS indentifiers.

branches: 1.1.1;
Initial revision