Added marking layer as bottom metal

gui/include/metadata_manager.hpp

@@ -5,7 +5,7 @@
 
 struct ObjectMetadata {
 	int status;
-	//std::string comment
+	std::string info = "\tNot applicable";
 };
 
 class MetadataManager {
@@ -14,6 +14,7 @@ public:
 	static bool save(std::string filename, std::string layername);
 
 	static bool addLayer(const Layer& layer);
+	static void markBottomMetal(std::string layername);
 
 	static ObjectMetadata& getData(std::string layername, int objectIndex);
 	static std::vector<ObjectMetadata> getLayerData(std::string layername);