Add another element to the texture tuple with a mask for the lighting.

Make needed changes in textures.py.

Because some textures have garbage in the alpha channel, this new method has some problems.

src/rendermode-spawn.c

@@ -102,9 +102,9 @@ rendermode_spawn_occluded(void *data, RenderState *state) {
 }
 
 static void
-rendermode_spawn_draw(void *data, RenderState *state, PyObject *src, PyObject *mask) {
+rendermode_spawn_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
     /* draw normally */
-    rendermode_overlay.draw(data, state, src, mask);
+    rendermode_overlay.draw(data, state, src, mask, mask_light);
 }
 
 RenderModeInterface rendermode_spawn = {