tweak SSAO to be weaker now that it's been de-linearized, and totally nerf the...

tweak SSAO to be weaker now that it's been de-linearized, and totally nerf the shadow blur dist factor since it helps more than hinders now that the shadow-smoother is more relaxed about edges at great distances.
(transplanted from e6227fac98097154c46454228825a5a1c0e8a63e)