[Feature Request] Automatically disable CSM on maps with no skybox.

[ScottVordem]

There is a small amount (don't know how small) of maps that intentionally do not have a skybox, or don't have the skybox "exposed" in the map.

These are generally interior maps with no outside environment or underground based maps.

It would be pointless to have CSM on since the shadows won't go through anyway.

An example map is RP_Subterranean