use new libdiscid 0.6.0 device detection if available

On Windows we currently use `D:` as default, but starting with libdiscid 0.6.0 the first actual disc drive is detected, which is much more usable.
So we should use that.

Cdradao doesn't understand drive letters on Windows, so we should make sure that still works.
I am not really sure if the current code actually works with cdrdao on windows (if drive is `D:` then cdrdao is given D as drive letter, but not otherwise?).