This PR adds support for JW Library 14, which brought with it some changes in the backup structure.
For now, go-jwlm won't be able to merge playlists yet. Support for it will be added in a future version. Until then, playlists will be removed during the import.
Also fixed a couple of bugs and improved structure for some tests.
coverage: 89.384% (+3.3%) from 86.118% when pulling 24670b14b4199d1b17ce7fae1e32d0dffc10f16e on playlist_version into 39bf323161784ff5af340ae491cd3e21cb21f4b2 on master.
This PR adds support for JW Library 14, which brought with it some changes in the backup structure. For now, go-jwlm won't be able to merge playlists yet. Support for it will be added in a future version. Until then, playlists will be removed during the import. Also fixed a couple of bugs and improved structure for some tests.