TextureCacheBase: Support dumping individual mipmaps.

Source/Plugins/Plugin_VideoDX11/Src/TextureCache.h

@@ -49,7 +49,7 @@ private:
 			const float *colmat);
 
 		void Bind(unsigned int stage);
-		bool Save(const char filename[]);
+		bool Save(const char filename[], unsigned int level);
 	};
 
 	TCacheEntryBase* CreateTexture(unsigned int width, unsigned int height,