Fix handling of 1/light_y when y was tiny but getting even tinier.

Add similar adjustment to shader version of same calc.

Make a distinct class3/lighting/lightV which boosts to WL levels (* 2.0)
and make lighting without WL atmo enabled use class 2 or below.

Make forward shaders (alpha and materialF with alpha-blend mode on) more consistent with deferred lighting.

Fix incorrect discard on fullbrights w/ alpha mask and cutoff > 1.

SL-10901, SL-10946

Limit influence of refraction scale to avoid pulling in lots of background 'deep blue' pixels never written in the distortion map pass.

Bias shadow sampling and allow control of how dark shadows are (clamped ambient).

Fix flicker even in no shadow ALM from pow on final_da.

Shadow acne at Midday still present.

SL-1491

Modify handling of additive to make extreme range of glow focus/size safe from lens flare artifacts.

SL-10996, SL-10997, SL-10970, SL-10967, SL-10856

Restore light sum loops to fix broken ambient.

Remove all refs to now unused calcFragAtmospherics.

All paths now use the same atmospheric transport calcs.

Revert fix for 10901 because knock-on is causing other issues.

Add directory names to sentinels in shaders so shaders with same filename can be differentiated in nSight while debugging.

SL-10966

Don't re-range density multiplier twice.

Fix merge error from 6.2.1 EAM merge.

SL-10967

Make fullbright transport look closer to normal transport so fullbright objects reflect distance.

SL-10966

Fix use of density and distance multipliers in atmospherics to use original pre-EEP range instead of FS expanded range.

Modify additive calc to restore old behavior (probably reverts fix for "lens flare" bug).

SL-10983 [EEP] Add a search box to the "My Environments" floater

SL-10988

Make moon disc image render only if current or previous textures are available.

SL-10957 [EEP] Add Reset button to revert to shared environment

Tweak forced frag depths for sun/moon disc images to resolve depth fighting with hills etc.