Feature1499

[Alzamer]

This PR adds a blacklist. Blacklisted tracks are excluded from the play queue. The user can delete tracks from the blacklist in the preferences.

[nukeop]

Hi, and thanks for the PR. Seeing as this is a pretty complex feature, could you please let us have a look at some screenshots? And would you mind adding a test or two for the happy path and some edge cases? Also, the areas where you've added this are already covered by snapshots which will need to be updated. I'll have some more remarks regarding style later on.

Regarding the functionality, the way you wrote it so that whenever the queue changes, it's scanned, and the blacklisted items are removed. Since the point of this feature is to ensure that the autoradio doesn't add blacklisted songs to the queue, this can cause a situation, where it adds a blacklisted song anyway, and it's removed afterwards, causing playback to stop (because it won't retry adding another song). A better way to handle this would be to modify the way autoradio picks songs to play, and blacklist them at that stage. For example, they could be filtered out, and if there are no songs left, it could search one more time with increased craziness until it finds something that's not blacklisted.