man pages: add missing commas between subordinate and main clauses

jmc@ dislikes a comma before "then" in a conditional, so leave those
untouched.

ok jmc@

Replace "function call" with "function" when referring to a function
(well, a syscall, but this is the established practice) in the general
sense.

ok jmc@

use .In rather than .Fd #include

no longer any need to quote macro lines with >9 args;
From: Jan Stary

Various updates, mostly to SYNOPSIS, ERRORS, and STANDARDS, but
some other fixes included...

*at() function ERRORS description suggested by matthew@

ok deraadt@

remove dead Xrs to update.8;

convert to new .Dd format;

update(8) is an in-kernel process;
from jared yanovich;

Remove the advertising clause in the UCB license which Berkeley
rescinded 22 July 1999. Proofed by myself and Theo.

section reorder;

most of these is v2, not v6

Another round of man page cleanup, this time to remove more hard sentence
breaks and getting rid of short lines, making these files easier to work with.

- change references to nil to null; tschroed@acm.org
- remove trailing spaces from end of lines
- add some .Dv
- change -1 to \-1, so `-' is taken as a negative sign
- other misc formatting fixes

remove argument from .Os macros so value in /usr/share/tmac/mdoc/doc-common
is used instead; kwesterback@home.com

make function names the correct case

fix openbsd tag

initial import of NetBSD tree