Betrayer: Partial fix for light shafts

This adjusts the blur origin, which fixes the light shafts. Only problem is
that the sun highlight is not adjusted - not a problem for the normal world
since the sky is white, but it means the sky looks a bit smeared in the
otherworld.
Betrayer: Add two more shaders that use TextureSpaceBlurOrigin

Because the lightshaft fix isn't perfect yet - the shafts are good, but the sun
in the otherworld is smeared and the shafts extend to uncomfortably different
lengths in each eye. Since these shaders use the same input as the light
shafts, it stands to reason that they are broken in exactly the same way.
Betrayer: Completely fix light shafts

Hooray! This game might actually be glitch free now!

Removed the ability to disable light shafts - why would you want to disable
that which is perfect?

Need to check if there is still any issues with the enemies, but they are very
uncooperative and move around a lot, so it's hard to tell.

I'll have to play through once more to be sure - there was one minor broken
effect near the end (fire), but it's concievable that one of the other ghosting
fixes or Eqzitara's fixes got it as well.
Betrayer: Add hotkeys 5,6,7,8,9 & 0 to change UI depth

I default to 0.995 which is pretty far into the scene, but feels more
comfortable to look to the UI from the scene and back again than lower values.
1.0 is too far and feels behind everything (because by definition it is).

I recognise that others may not be used to the UI being so far back, so I've
added a bunch of presets that other people can use.