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).

Allows visual editors to be used.

XXX shares database file with IPv4 one (0.0.127.in-addr.arpa)

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

Submitted by: kevlo@

calloc(), and realloc().  Idea from NetBSD.

DAD before the actual rtsol(8) run happens later.  and since it will rtsol,
it is going to be up in any case.

XXX both "dhcp" and "rtsol" has keyword *down* at the end.  is it okay?

sleep for net.inet6.ip6.dad_count seconds to ensure that IPv6 DAD is completed.
TODO: rtsold (rc.conf line), manpage

to do this,
1. in sysctl.conf, add these lines:
net.inet6.ip6.forwarding=0
net.inet6.ip6.accept_rtadv=1
2. in hostname.foo, add
rtsol
specifying two or more interfaces with "rtsol" may result in strange
behavior - ipv6 spec does not permit multi-interface node to be autoconfig'ed.

- multiple entries support (read: aliases)
- inet6 support
- support for comments (#)
(look for hostname.if(5) commit for syntax details)

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