(svn r19723) -Add: a simple sprite alignment helper. It does not store the new offsets anywhere so as soon as the sprite is reloaded the offsets are gone (use a bigger sprite cache if this happens). Also anything that reloads NewGRFs (new games, loading games or (re)applying NewGRFs) clears the sprite cache and as such resets the offsets.

src/newgrf_debug.h

@@ -57,4 +57,9 @@ GrfSpecFeature GetGrfSpecFeature(TileIndex tile);
  */
 GrfSpecFeature GetGrfSpecFeature(VehicleType type);
 
+/**
+ * Show the window for aligning sprites.
+ */
+void ShowSpriteAlignerWindow();
+
 #endif /* NEWGRF_DEBUG_H */