Remove an extraneous check for dtoa returning Inf/Nan

Decimal point was missing for some exponential output
Only divide sign by 10 once per loop
Add a missing NUL terminator for one case
If there is no whole number portion, print a leading zero (e.g. 0.1 not .1)

1997 (yes, really).

Add new sys/_types.h header
Include machine/_types.h or sys/_types.h where applicable

drivers, and to wscons as the console; a few parts borrowed from OpenBSD/macppc
as well.
Currently only working with displays configured in 1bpp or 8bpp modes; this
limitation will be worked on ASAP.
Tested by claudio@ kettenis@ martin@ nick@ and I on various models. X11 changes
coming soon.

Use correct values for _POSIX_TTY_NAME_MAX and _POSIX_LOGIN_NAME_MAX
Define MAXLOGNAME in terms of LOGIN_NAME_MAX
OK krw@

separate errno.h.  sys/errno.h now only contains errno values (which
is included byerrno.h).  OK deraadt@

dev/fd comment and point to fd(4).

a long time, but i'm a bloody slacker...

OK deraadt@

in sys/cdefs.h) instead of _FOO_SOURCE.  Also fix several namespace
pollution issues, including the byte order defines.  OK deraadt@

validate this condition and reject multicast traffic on failure.
ok todd@ naddy@

also start ntpd at this time.
discussed with jmc@; ok deraadt@

and remove fallback code. If somebody is dumb enough to make the
sysctl fail using systrace, he deserves what he gets. Saves 7 syscalls
on process startup.
looks good miod@ ok deraadt@ tedu@

userland-visible sys/select.h.  Consistent with what Net and Free do.
OK deraadt@, tested with full ports build by naddy@.

/root instead of hard links to them.  This way multiuser only changes
a user makes to the to the ones in /root do not screw them over for
getting into single user easily when the have to.
ok millert@

the official assignment by the IANA for the IEEE 802.11f Inter Access
Point Protocol on port 3517 is 802-11-iapp, we use it as an alias.
ok jakob@, deraadt@

should take intptr_t, not int, but we don't presently have intptr_t
available from unistd.h.  OK marco@

ok millert@

jason@. Man page fixes by jmc@, prodding by jsg@. ok mickey@

(not really useful for now, it mostly helps some programs which want
to use it, it will become useful when we have full 16 bits locale).

ok henning beck