Now line buildings save/load works

src/modules/stream/road_lines_data.h

@@ -20,6 +20,9 @@ public:
 		float line_offset;
 		float normal_offset;
 		float y_rotation;
+		static void from_dict(struct line_building_data *b,
+				      const Dictionary &from);
+		Dictionary to_dict() const;
 	};
 	struct line_segment {
 		Vector3 p1;
@@ -48,6 +51,7 @@ public:
 	static void cleanup();
 	String get_road_lines_path();
 	void get_road_lines_key_list(List<String> *keys);
+	void load_data();
 	void save_data();
 	void process_lines(std::unordered_map<uint32_t, std::vector<Vector3> >
 				   &road_lines_nodes_hash,