Began reworking the network code

This commit devides SerialPacket into a series of different structures,
all decended from a common base class.

Using a union was not a good idea.

common/gameplay/room_data.hpp

@@ -30,6 +30,12 @@ struct RoomData {
 		FORESTS,
 		CAVES,
 	};
+
+	/* TODO: more
+	 * "multiple rooms system" using this structure
+	 * Pager
+	 * collision map
+	*/
 };
 
 #endif