sfdisk: add --parttype

The patch also makes --{id,change-id,print-id} deprecated in favour
of --parttype. The original --id is too generic option name and the
--print-id and --change-id are unnecessary and inconsistent with
another sfdisk options (e.g. we don't have --change-bootable)

Signed-off-by: Karel Zak <kzak@redhat.com>
sfdisk: cleanup usage() and long options

Signed-off-by: Karel Zak <kzak@redhat.com>