USIII support now largely working - please test!

[matthew green <mrg%eterna.com.au@localhost>]

hi folks.


please try out as many USIII systems that you can with -current, and
report back here details.  i'm curious to find out what happens where
now, and what else is needed.

some systems will requiring running GENERIC.MP instead of GENERIC for
now, and this means the installer won't work properly yet, but net
booting GENERIC.MP should work.

i've been largely testing on SB2000 and SB2500, but have also seen
reports of SB1000 and v120 working ok, but of E420R not being happy.


i've also been unable to reproduce problems with NFS writes that
a build to nfs objdir usually triggered.  i was able to build 5
releases before i shut the U60 down, that used to fail about 1/2
way through the first one.


thanks!


.mrg.