1) Fixed up some header locations
2) Replaced list of boot files with /kernel
3) Changed disklabel use in Makefile to conform to 4.4
4) Added size command in Makefile to get close estimate of bootblock
sizes. Total size of text and data must be below 64K, slightly
overestimated since a.out header subsequently gets stripped.
5) Various buffer sizes are set to 8192 bytes in sys.c. In 4.4 MAXBSIZE
is set to 64K which is too big for the bootblocks to deal with.
Submitted by: Paul Richards
