ites and masked walls with hard edges
* cvar [[rend-dev-mobj-bbox]]: debugging aid - render mobj bounding boxes (sized to match the box used for collision detection) for debug.
* cvar [[rend-dev-cull-subsectors]]: disable non-visible subsector culling for debug.
* cvar [[rend-glow-scale]]: multiplier for wall glow height
* Added more [[xg_dev]] messages. Reference types are printed by name i