Bring in the trivial differences between this code and John Hay's new

Bring in the trivial differences between this code and John Hay's new
code.  Added a copyright for the work I did to this file a couple of
years ago.  Add John's copyright too, since I'm sure I'll be pulling
more into this code.  This also implements a new -n option to not
allow breaking into the boot sequence which was original in the patch
John posted (not in the original i386 code I based this boot2.c on,
only the name is the same).  I haven't checked to see if he did that,
or if it was one of Sam's improvements.

Submitted by:	jhay@