Calculate the leadout from the sum of the track lengths.
* morituri/test/breeders.cue:
* morituri/test/cure.cue:
Adapt expected results for DISCID.
* morituri/image/table.py:
Add an assert for hasTOC() when doing .cue()
* morituri/test/test_image_toc.py:
* morituri/test/test_image_cue.py:
absolutize before cue()
* morituri/image/toc.py:
Add parsing of ISRC codes.
Add first part of CDTEXT stuff.
* morituri/test/test_image_toc.py:
Add test for converting .toc to .cue
* morituri/test/cure.cue
Add reference for converted cure.toc