Google Code-in

From the issue:

"The issue here is that morituri's own "musicbrainz id calculation" fails on CDs with data tracks on special places. For my IA fork I decided it wasn't worth my time fixing the custom calculation, and instead I added this commit: https://git.archive.org/archivecd/morituri/commit/8e108e239b15600315128b2e0cba0d4836f044d7 and set the value using the defacto discid library, which does get it right.

We probably do not want to use this hack, but I'm all for just throwing out the custom calculation code from morituri in favour of libdiscid."

The task will be to remove the current custom Disc ID generation code from whipper's codebase and replace it with function/method calls to libdiscid/python-discid. In the end, ripping a CD with data tracks at the start of the CD should not fail because the current MusicBrainz calculation fails. The CD may fail to rip at other stages in the ripping process, but that is not a part of this task.