Use python-discid instead of libdiscid.

Python-discid (http://python-discid.readthedocs.org) is a Python binding of libdiscid.
It resolves http://tickets.musicbrainz.org/browse/PICARD-503
Use discid/libdiscid drive auto detection, especially on first start

It will add default drive as returned by libdiscid to the list of known drives
Ie. on linux, list is : /dev/cdrom, /dev/sr0, /dev/sr1 (default link + 2 sata cd readers)

On first start it will populate the list with default drive provided by libdiscid,
which means Picard is now able to scan CD without going to Options (to set
cd reader) first, which was not the case before.