Support for animated/special WAD textures

[LogicAndTrick]

Archie from TWHL suggests: http://twhl.info/forums.php?thread=18410&page=7

Would it be possible for a tickybox or an option to choose between displaying all frames of an animated texture, or just the +0 version, previewing the animation?

If this was implemented, it'd be nice to also do the same for button textures and animate/render them in 3D. Additionally Goldsource also has support for randomly tiled textures, but rendering them would be quite difficult so just showing those in the texture browser would be enough.