limit on OPEN_MAX, modeled after bgpd

ok msf@ hshoexer@ krw@ millert@

hook the descriptors into the main poll and such.
we're not doing anything with the reply we recive yet, tho.
mostly hacked on the Frankfurt->Montreal flight, as batteries and those
horrible air canada seats permitted...

should only be 255.  You would think they would be the same but you'd be
wrong.

ok millert@

ok henning@

ok deraadt@

disabled.  Magne Oestlyngen.

ok deraadt@

for now, one can set the addresses to listen on

default to one IPv4 wildcard and one IPv6 wildcard one.

respectively instead of duplicating their values.

o _POSIX_CHILD_MAX increased to 25
o _POSIX2_RE_DUP_MAX renamed _POSIX_RE_DUP_MAX
o _POSIX_SYMLINK_MAX and SYMLINK_MAX added (same as PATH_MAX)
o _POSIX_SYMLOOP_MAX and SYMLOOP_MAX added (like MAXSYMLINKS)

it is just capable of answering (s)ntp4 requests with the local time
for now.
imsg/buffer and logging framework from bgpd, ntp protocol hackery
with Alexander Guy

scope so that passing a NULL digest is equivalent to the Pad function
(like it used to be).  Fixes skey w/ sha1 as noticed by David Krause.

with new binutils without tweaking datasize. ok deraadt@ millert@

deals with it at startup; noticed by wilfried, millert ok

ok krw@ deraadt@

- deny access to /etc/spwd.db, permit pwd.db instead
- fixes pr 3748
- cosmetics
"toss it in" deraadt@

reorder path to place /usr/X11R6/bin before /usr/local/{bin,sbin}
sync .profile PATH with .cshrc path
ok deraadt@, millert@