Blender Git Loki

fix smooth groups calculation

Review update: fix UI text; add comments.

Variable type change for `forward_axis` and `up_axis`.

Add exporter specific code.

Files like `io_obj.c` which contain both importer and exporter code
are also here.

Differential Revision: https://developer.blender.org/D8754

Merge branch 'property-search-highlight-tabs' into property-search-all-tabs-v2

Merge branch 'property-search-highlight-tabs' into property-search-all-tabs

Merge branch 'property-search-start-end-operators' into property-search-highlight-tabs

Property Search: Use runtime struct properly for seach string

Merge branch 'property-search-highlight-tabs' into property-search-all-tabs

Merge branch 'property-search-start-end-operators' into property-search-highlight-tabs

Merge branch 'property-search-single-tab' into property-search-start-end-operators

Property Search: Fix storing search string in runtime struct

Property Search: Use pointer for properties space runtime struct

Merge branch 'master' into soc-2020-io-performance

GPencil: Change Holdout tooltip

Property Search: Add explanatory comment

GPencil: Change Holdout to Solid Stroke only

Now the Holdout only supports:

* Solid Strokes. (Textured strokes not supported)
* Solid Fill.
* Texture Fills (Alpha section of the texture).

Merge branch 'property-search-add-theme-color' into property-search-single-tab

Merge branch 'property-search-move-context-to-panel' into property-search-add-theme-color

Merge branch 'property-search-button-label-pointer' into property-search-move-context-to-panel

Merge branch 'master' into property-search-button-label-pointer