Fix a texture bug reported by Hidan
Here : https://wildfiregames.com/forum/index.php?/topic/24633-persian-temple-textures-missing/
Based on a tweak by wowgetoffyourcellphone mixed with a personal one.
- Move Old Pers struct to the old public as it shouldn't be used anymore.
- Use Normal and specular textures where available.
- Make sure the pers png is used from now on.