a PMBR. Make sure the create command creates a PMBR as well
(if not already present).
o When parsing the MBR, explicitly check for a PMBR and create
a PMBR map node if one is found.
o When parsing the MBR, recurse to handle extended partitions.
This allows us to flatten nested MBRs when migrating to a
GPT.
o Have the migrate command bail out if it encounters a partition
it doesn't know how to migrate. This avoids data loss.
o Change the output of the show command so that the UUIDs of the
GPT partitions fit on the same line.
o Show when partitions are extended partitions and add the PMBR
type.
Approved by: re (blanket)