/*
 * Return information about a specific song in the playlist.
 *
 * This method raises an Xmms::Error exception if XMMS is not running.
 *
 * Examples:
 *   title, file, time = remote[45] # get info about the 45th song
 *   info = remote.get_entry 45 # get info about the 45th song
 *
 */
static VALUE xr_pl_ary(VALUE self, VALUE pos) {