Very rudimentary, lots of error checks missing, but it works.
Dont do an ls on two different CD's though, it will eat your
changer mechanism for lunch :), this clearly needs some more
thought. Until then this will enable those with changers to
mount their multible CD's and doing "sensible" work....
Thanks to Andrew Gordon <arg@arg1.demon.co.uk> for donating a drive
(a NEC CDR-C251 4x4) that makes this possible to develop.