Viewtype per platform / fallback to next type of artwork.

[ArjanNL]

I would like to see an option to change views per platform. For example to have snes showing 3d boxes, nes showing 2d carts, etc. Right now you can only choose 1 view globally, but if let's say my nes collection has all the 2d carts, but snes doesn't, snes shows an empty spot, which i don't like. If you could choose a viewtype per platform you are able to avoid this.

A fallback to the next type of artwork if certain artwork is missing would be nice as well to prevent empty spots.