- check superblock checksum in examine
- report "chunk" or "rounding" depending on raid level
- report "linear" instead of "-1" for raid level DONE
- decode ayout depending on raid level DONE
- get Assemble to upgrade devices if force flag.
- --verbose and --force flags.

- set md_minor, *_disks for Create
- for create raid5, how to choose between 
   all working, but not insync
   one missing, one spare, insync