- refer to the section 4 manual page for every device target, whenever
possible
- repair a few minor quoting errors
- repair a few sorting errors
- fix a few device descriptions (ideally they would be synched with the
.Nd line of their manpages, but we are not there... yet)
- minor mdoc fixes
Thanks to jmc@ for review and a lot of constructive criticism.

- 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.

- add bpp devices

too small

pointed out by todd@

ok, deraadt@

ok miod@

thanks to nick@openbsd.org for finding this
thanks to nick@openbsd.org, drahn@openbsd.org, and lurene@daemonkitty.net
for testing on short notice!

As requested by deraadt@