Use of the latter caused the 1st and 2nd stage boot loaders to occupy
over 64k of memory. This caused them to fail on a 4Mb mvme147 since
they are loaded at 0x3f0000.
Reported by Kristen A. McIntyre and Maxime Kurkdjian.
exec_mvme.c: from sun3 port, adapted by me. I also fixed a bug that
prevented ZMAGIC kernels from running.
libsa.h: new file by me
parse_args.c: by Theo de Raadt from OpenBSD with slight revisions from by me
to make it fit the new format.