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@.

with r1.18. 'rm' and 'il' were removed from getdiskbyname() in 2009
with r1.19. The associated disklabel fields were recycled for other
purposes.
Another 'harmless' part of the larger disklabel cleanup diff.
ok deraadt@ as part of that larger diff.

out that sparc64 iso at least does not boot. Retain the svnd -> vnd
changes that happened after the original commit.

the boot cd image.
ok 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

too small

Cleanup so all Quantum disks are now Capitalized.