(no need for a "common" subdir which contains stuff only really
referenced by one other directory)
- use Makefile.tarfloppy instead of local code to build floppies
- use .WAIT in the top-level Makefile appropriately
- install inst.fs directly from ramdisk/Makefile rather than providing
separate inst/Makefile
- Remove historical `script' installer, which was provided for
4MB RAM systems.
- Instead we provide `floppy-root' installer, which is composed
of 2 floppies just like the installation system used in the netbsd-1-2
days; one floppy contains (GENERIC) kernel and the other contains
the miniroot.
- The miniroots for both `ramdisk-root' installation system and
`floppy-root' installation system are identical.