Blender Git Loki

UI: Cleanup - Remove Show Panel Header and Background

A toggle for this is no longer required now that both header and background
colors are RGBA (disabling Show Header is the same setting the alpha to 0).

Thanks Brecht for reviewing!

Fix: melanin randomization to the linear quantity

Fix T55776: crash with multiple windows and reload new.

There were a number of cases where immActivate() and immDeactivate() could
get out of sync, causing crashes due to using a freed mutex lock. Refactor
the code now to hopefully avoid this always.

UI: tweak image menu layout to match file menu more.

Merge remote-tracking branch 'origin/blender2.8' into temp-eeveelightcache

# Conflicts:
# source/blender/draw/engines/eevee/eevee_lightprobes.c

GPUTexture: Fix GPU_texture_read for depth stencil format

Eevee: LightCache: Use render visibility to select the probe

If a probe is not visible during render, it will not be selected to be
baked into the lightcache.

Eevee: LightCache: Fix cache validation.

Eevee: LightCache: Fix wrong mipmap size

Eevee: LightCache: Fix problem caused by probe sorting

Type qualifier typo

Ty nirved

Merge branch 'blender2.8' into greasepencil-object

Fix: apply Coat mod TO THE ROUGHNESS, not variance

UI: hide status bar constraints when not used

Fixed artifacts in bevel with high profile and segments

UI: hide status bar items when

WM: add utility function to refresh status bar

Linearize melanin concentration

This commit includes factoring remappings into new functions, as well as
adjusted defaults for maintaining roughly the same brownish hair.
(In reality, Melanin 1.3 = New Melanin 0.8054375, so I truncated the
extra decimal places.)

Merge branch 'master' into blender2.8

Cleanup: use const transform args