Finally implement the "auto" disktype. It attempts to get all the

Finally implement the "auto" disktype.  It attempts to get all the
required information from the driver, and produce a virgin disklabel
for it.  The latter might be further edited with `disklabel -e' to
satisfy the user's need.

The magic sequence is:

	disklabel -r -w sdX auto
	disklabel -e sdX