floppy (and there's not the same RAM contraints that *-tiny has),
fold rescue-small into boot-small and deprecate the former.
The "all in one" boot-small is only 100KB larger on the second floppy.
../../common/Makefile.mdset supports building multiple copies of the
same kernel (as long as they're to separate filenames).
Now there's no need to set FLOPPYKERNDIR, as it now defaults to instkernel.