Add name field to ContentFeatures

src/nodedef.h

@@ -138,13 +138,12 @@ struct ContentFeatures
 	// the texture atlas
 	std::set<std::string> used_texturenames;
 	
-	// True if this actually contains non-default data
-	bool modified;
-
 	/*
 		Actual data
 	*/
 
+	std::string name; // "" = undefined node
+
 	// Visual definition
 	enum NodeDrawType drawtype;
 	float visual_scale; // Misc. scale parameter