function setShufflePlaylist(playlist, shuffle) {
    _config2.default.playlists[playlist].shuffle = shuffle;

    if (_config2.default.playlists[playlist].shuffle) {
      shufflePlaylistSongs(playlist);
    } else {
      _config2.default.playlists[playlist].shuffle_list = [];
    }
  }
Sets the shuffle state for a playlist

@access public
@param {string} playlist   The key of the playlist we are shuffling.
@param {boolean} shuffle   True when we are shuffling the playlist, false when we turn off shuffle.