function sync(currentTime) {
    /*
    Set current time display.
    */
    syncGlobal(currentTime);
    syncPlaylist(currentTime);
    syncSong(currentTime);
    syncSongInPlaylist(currentTime);
  }
Visually displays the current time on the screen. This is called on
time update for the current song.

@access public
@param {object} currentTime 					- An object containing the current time for the song in seconds, minutes, and hours.