Log through a GameLog autoload instead of print()

GameLog.debug() prints only in debug builds, and GameLog.warning() reports
problems such as unexpected server data or failed downloads.

SongObject.gd

@@ -42,12 +42,12 @@ func get_song_info() -> String:
 		return "??? - ???"
 
 func add_point(player_id: String) -> void:
-	print("add_point")
+	GameLog.debug("add_point")
 	if !players_given_point.has(player_id):
 		players_given_point.append(player_id)
 
 func remove_point(player_id: String) -> void:
-	print("remove_point")
+	GameLog.debug("remove_point")
 	players_given_point.erase(player_id)
 
 func _to_string() -> String: