P0-A6: Part 697: Sky Render Order

I have finally fixed a comple issue with the Sky Rendering order.

I was having issues with distance object (such as planets, the Aurora effect, etc) appearing in front of the Clouds.

This was particularly noticeable in very bad weather, when there would be heavy cloud, which should completely obscure the sky.

This is now fixed, and planets and distant objects are now completely hidden during overcast skies.