Performance of main client loop up to 2x faster In places, up to 3 times faster

NOTE 1: This does not mean a 2x increase in framerate. Increase in fps may be up to 1-2fps
NOTE 2: This local 'caching' of settings is not optimal and an alternative solution will be worked on after 0.4.11 is released

src/client.h

@@ -562,6 +562,9 @@ private:
 	// Used for saving server map to disk client-side
 	Database *localdb;
 	Server *localserver;
+
+	// TODO: Add callback to update this when g_settings changes
+	bool m_cache_smooth_lighting;
 };
 
 #endif // !CLIENT_HEADER