Add texture overriding

src/nodedef.h

@@ -335,6 +335,11 @@ public:
 	*/
 	virtual void updateAliases(IItemDefManager *idef)=0;
 
+	/*
+		Override textures from servers with ones specified in texturepack/override.txt
+	*/
+	virtual void applyTextureOverrides(const std::string &override_filepath)=0;
+
 	/*
 		Update tile textures to latest return values of TextueSource.
 	*/
@@ -378,4 +383,3 @@ public:
 };
 
 #endif
-