no more dupes in playlist
no more dupes in playlist

Checks if a track is already in playlist,
if it is we dont add it again

foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm