Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 access_token(Arg1, Arg2)

 playlist_to_csv(Arg1, Arg2, Arg3)

 run_curl(Arg1, Arg2)

 run_curl(Arg1, Arg2, Arg3, Arg4)

 retrieve_all(Arg1, Arg2)

 retrieve_all(Arg1, Arg2, Arg3, Arg4)

 playlist(Arg1, Arg2)

 playlist_track(Arg1, Arg2)

 track_name(Arg1, Arg2)

 track_artists(Arg1, Arg2)

 track_info(Arg1, Arg2)

 playlist_info(Arg1, Arg2)

 playlist_track_info(Arg1, Arg2, Arg3)

 test(Arg1)