Blender Git Loki

Eevee: Split irradiance functions to their own new file.

Probe: Fix probe panel

Eevee: Disable specular when rendering probes.

This prevents weird reflections and really strong indirect lighting.

Probe: fix grid default resolution.

Eevee: Add Irradiance Grid support

Early implementation. Slow and still has quality
3 ways of storing irradiance:
- Spherical Harmonics: Have problem with directionnal lighting.
- HL2 diffuse cube: Very low resolution but smooth transitions.
- Diffuse cube: High storage requirement.

Also include some name change.

Probe: Add grid probe parameters.

PYAPI: Fix mathutils doc structure

Merge branch 'master' into blender2.8

Make whole ID copying code use const source pointer.

Noisy change, but safe, and better do it sooner than later if we are to
rework copying code. Also, previous commit shows this *is* useful to
catch some mistakes.

Fix three obvious mistakes in brush/mask/cachefile ID copying.

They were modifying some source ID prop, instead of copied version of
it... Found while making all source of ID copying const. ;)

PYAPI: fix documention structure of bpy.app

Fix missing toctree for bmesh submodules

PYAPI: Fix freestyle submodules without tocrees

Fixes 6 compile warnings
Follow up on rBf87ca5f1c314f67353b6111d3647aef159dc07c6

Add an option to free scene without doing id-counters

This is similar to some other datablocks. Mainly applies to collections,
so freeing scene does not involve changing any non-directly owned data.

There are two main usecases foreseen for the future:

- Less CPU ticks on bmain free, where everything is freed anyway and
there is no need to preserve id counters.

- Easier freeing of temporary data, including data which is used by
depsgraph's copy-on-write mechanism.

Neither of those are currently implemented, but will be shortly.

Implement hair in eevee

New implementation of hair for Eevee.

Note: A hard coded "transmission" property is being used. This should
eventually be exposed to the UI, possibly in the form of SSS
properties.

Temporarily disable material preview (T51796 workaround)

This stops the memory breakage caused by the material preview jobs,
to enable the new hair drawing implementation.

(This should be reverted once T51796 is actually fixed!)

Merge branch 'master' into blender2.8

Depsgraph: Cleanup, indentation

Merge branch 'master' into blender2.8

Remove unused bmain argument from BKE_libblock_free_data