Remove bogus targets.
Allocate partition letters as follows:
lowest offset "flags & CHUNK_IS_ROOT" gets 'a',
lowest offset "subtype==FS_SWAP" gets 'b'
the rest is allocated in offset order from this sequence "defghab".
This will generally make sense.
Added rules to complain if more than one CHUNK_IS_ROOT or more than one
FS_SWAP per FreeBSD chunk.
Set CHUNK_IS_ROOT on the 'a' partition in Open_Disk.
Run Fixup_Names in Open_Disk.
Made an All_FreeBSD() function.
Added a cmd-line interface (lowest rank) to the tst01 program.
The tst01 program is harmless (worst it can do is coredump), but it
is instructive to run, you can see what the slice-code things of your
disk...
