now by default mount the last data track (thus last session), as
opposed to the very first session it has been mounting previously.
This is consistent with the ISO9660 multi-session idea, and the way
other operating systems are working.
There's support to mount arbitrary sessions using the -s option. This
way, you can simulate multi-session CDs on something like vn devices
that don't support CDIO* ioctl commands. You can also force the
historic behaviour with
mount -t cd9660 -o -s=0 /dev/cd0a /cdrom
