merge in support for hp300 from Utah

get rid of spurious #define in user.h

initialize u_start

no longer have per user quota structures

swapper and pagedaemon have names set in p_comm.

controlling terminal is a vnode

Keith Bostic says not so quick with the copyright notice

file system initialization is now all done by vfsinit

initialize systemwide vnode table

all zeros isn't good enough for signal initialization now

add memory filesystem initialization

initialize other fields in the buffers

update reference counts on vnodes using VREF

gather initialization code for nameidata into ndinit()

use uio structure in nameidata rather than constructing a new one

lint; new naming convention

integrate back branch -7.5.1.1

merge in vnode changes

init KTRACE variables

../machine => machine

posix style job control - new process groups

lint

mv more tahoe stuff to machdep; clk_enable was dup;
allow root to be mounted readonly

rearrange initialization of buffers so can be used during configure

hide tahoe-ism in enablertclock(); call startrtclock so tahoe can set interval timer