number of audio* nodes from 3 to 1 on vax, since none of the audio-capable
vax can receive another audio device as expansion (until we get TURBOchannel
support with DMA on VS4k/90).
ok deraadt@ todd@

discussed with jsing and millert

feedback from miod@ and deraadt@

i386.  Stop abusing it on other archs for controling a shutdown by
pressing the soft power button:
* Add a MI sysctl hw.allowpowerdown; if set to 1 (the default) it
allows a power button shutdown.
* Make acpi(4)/acpibtn(4) honor hw.allowpowerdown.
* Switch the various power button intercepts on landisk, sgi, sparc64
and zaurus over to hw.allowpowerdown.
* Garbage collect the machdep.kbdreset sysctl on all archs other than
amd64 and i386.
ok miod@

In effect, this removes the "old" vndX nodes, and renames
the svndX nodes to vndX.
Old svndX nodes will still continue to work though, for now.
Cleanup accordingly.
ok deraadt@, todd@
comments and ok on the man page bits from jmc@

explicitly. OK dlg@ & todd@

Prodded by jmc@.

General huzzahs.
"go for it" deraadt@

disklabel the "HP C3010 / Cranel 2.0GB Fast SCSI2 H10" crammed inside your
palm device, but that's the price of progress.  hopefully i didn't whack
anything important.
ok deraadt

ok todd@ krw@ deraadt@

get it in! jsing@

ok jasper@ (also compile tested)

ok miod@, deraadt@, todd@.

console case; ok deraadt@ miod@

kettenis@; ok kettenis@ miod@