ok deraadt@

from Jon Mosco;

ok marc@ fgsch@

- homogenize section order
- sort devices inside sections
- make sure all platforms provide a local target (sigh)
- remove a few dead devices not worth mentioning on a few arches while there.
disabused ok deraadt@

ioctl(2), an unprivileged process may allocate a pty and have its owner
and mode set appropriately.  This means that programs such as xterm and
screen no longer need to be setuid.  Programs using the openpty()
function require zero changes and will "just work".
Designed by beck@ and deraadt@; changes by beck@ with cleanup (and
a rewrite of the vnode bits) by art@ and tweaks/bugfixes by me.
Tested by many.

The latest versions are at http://www.ata-atapi.com/hiw.htm.
Discussed with nick@ and jmc@.  ok deraadt@.

problems noted by fgsch@ and deraadt@

original commit was done?)

disabled by default.
Enable with sysctl -w machdep.userldt=1
This will allow people to use the few ports that require this functionality
to work without requiring the user to recompile a kernel.
The option USER_LDT remains in order to not increase size on the
installation media. It is now enabled in GENERIC.
Per espie@'s idea, but my diff was much simpler than his; ok deraadt@

ok henning@

ok henning@

pointed out by todd@

ok, deraadt@

ok miod@

As requested by deraadt@

ok millert@