Cluebat and OK deraadt@

SGI has 8 kernels, so the file is 113MB!

flags in the disklabel. These flags were discarded in 2006.
Remove documentation for and instances of 'ty'. Add instances of
'dt' that were missing. Use 'floppy' as the value of 'dt' for all
floppies and 'rdroot' for all boot images/miniroots.
Add 'rdroot' to dktypenames and an associated #define DTYPE_RDROOT,
since 'dt' values are parsed by matching entries in dktypenames[].
Slightly tweaked part of larger cleanup diff previously ok deraadt@.

contain both a 2048-byte sector ffs filesystem, and a 512-byte volume header,
so that the IP27 boot magic^Wuglyness recently added to the boot-only cd-rom
(cdXX.iso) can be applied as well.
The full-blown installation iso can now boot on IP27/28/30/32/35.

provide IP22 and IP28 kernels, as well as the ECOFF bootblock.
No objection from deraadt@

disklabel the "HP C3010 / Cranel 2.0GB Fast SCSI2 H10" crammed inside your
palm device, but that's the price of progress.  hopefully i didn't whack
anything important.
ok deraadt

enlarge bsd.rd filesystem; this in turn causes a cd oflow, so enlarge
cd filesystem.
ok jsing@ deraadt@

(although for now our cd images fail to boot on IP27 and IP30).

and mention this in the Makefile so that this hopefully doesn't get broken
next time the size is modified. Repairs install45.iso.

ok krw@