Normalize backslashes in track paths to fix broken playlists on Windows

[GilgameshxZero]

On Windows, [email protected] adds tracks with slash paths ("C:/path/track.mp3"), but interprets playlist tracks with backslash paths ("C:\path\track.mp3"). Without resolving track paths (thus normalizing slashes to backslashes), playlists will never find tracks to add, and thus will always be empty.

You can see this by creating a test directory, and placing a track.mp3 and a playlist.m3u in the directory. In playlist.m3u, have one line adding the track:

track.mp3

Upon adding the directory to the library on [email protected], the playlist will be empty (here, resolved filePath is without the resolution; I just forgot to take out the console.log):

However, by resolving the filePath for each track, the playlist will be interpreted correctly:

The PR also updates a small number of outdated comments.

[martpie]

Good catch, thank you very much!

[martpie]

I will try to release this tomorrow 👍