fdisk: (dos) use libfdisk to ask for partition type

Signed-off-by: Karel Zak <kzak@redhat.com>
libfdisk: move mbr code to the library

Signed-off-by: Karel Zak <kzak@redhat.com>
fdisk: (bsd) clean up BSD_LABEL* macros

Signed-off-by: Karel Zak <kzak@redhat.com>
libblkid: move bsd definitions to pt-bsd.h

Signed-off-by: Karel Zak <kzak@redhat.com>
fdisk: (bsd) use pt-bsd.h

Signed-off-by: Karel Zak <kzak@redhat.com>
fdisk: (bsd) use macros from pt-mbr.h

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