- Cleaned up documentation, with a real man page.
- Support for clusters larger than 16K.  This would require changing
  a lot of the SYSLINUX internals so we can read partial clusters;
  change the current "cluster pointers" to become
  "cluster:sector pointers".
- Support initrd that span multiple input media?
- Support a small set of DOS system calls for COMBOOT images?  (Serial
  console support makes this particularly desirable.)