o utmp lives in /var/run, not /etc
o document EX_CONFIG

for XPG conformance.  We don't use it but programs might check for it.

Really, there should be a way to make configurable by the admin
at runtime (say, a gettmpdir() function).

(ok art@)

in sync with kame and bsdi.

this will help future apps from complexity of SIOCGIFCONF.
NOTE: getifaddrs(3) uses sysctl interface, not SIOCGIFCONF.

off_t to be visible in stdio.h even in strict ansi mode.  This is needed
for ftello()/fseeko() and it allows us to remove the horrible fpos_t hack.

Also make fsetpos() and fgetpos() use fseeko() and ftello() respectively
since fpos_t is actually a 64bit type.

is changed, based on discussion in ipngwg scoped address cabal.
past code:	fe80::1@de0
now:		de0%fe80::1
this will be in sync with next extended address format proposal
(which should be final - I don't want to make this kind of change again).

rcmd(): IPv4 only
rcmd_af(): af independent
ruserok(): af independent
iruserok(): IPv4 only
iruserok_sa(): af independent

removed functionality:
new code will not return AF_LOCAL addrinfo struct.
added funtionality:
SOCK_RAW is permitted as ai_socktype (no servname allowed).
draft-ietf-ipngwg-scopedaddr-format-00.txt

Fix prototypes, propagate const where applicable.

Redefining it as a typedef is an error, as it prevents overloading
on e.g., int/wchar_t separately.

Install it under /usr/include

ones that are useful for all protocols, not just IPv6).

__null is a magic constant of integral type that converts to a null pointer
as should be, but warns for ambiguity when used to resolved an overload
between an integral type and a pointer type.

(this follows FreeBSD and Linux. Single Unix 2 is still illogical)