RBD diff format to VHD disk conversion tool

    Usage:
        vhd2rbd --vhd <vhd_file> --rbd <rbd_file> [-p] [-m] [-v] [-d]
        rbd2vhd --rbd <rbd_file> --vhd <vhd_file> [--uuid <vdi_uuid>] [-p] [-m] [-v] [-d]
        rbd2raw --rbd <rbd_file> --raw <raw_file> [-p] [-m] [-v] [-d]
        rbd2nbd --rbd <rbd_file> --nbd <nbd_server> [-p] [-m] [-v] [-d]