Blender Git Loki

Cleanup: GPU: Encapsulate glProvokingVertex

Cleanup: WM: Encapsulate stereo draw buffers binding

Cleanup: KnifeTool: Replace glPolygonOffset by GPU_polygon_offset

Cleanup: GPU: Encapsulate clipDistances

This also remove some non functionnal state changes that were left
from legacy code.

UI: Use property split for custom property edit popover

The panel looks out of place with the rest of Blender's UI and the
text is cropped. With property split turned on and a few smaller
tweaks these issues are fixed.

| Before | After |
|{F8700181}|{F8700183}|

Differential Revision: https://developer.blender.org/D8322

Outliner: Add gpencil effect props sync

Add properties tab sync when gpencil shader effects are selected.

Outliner: Draw gpencil shader effects in the tree

Draw the gpencil visual shaders in the outliner tree. Adds new TSE
types.

Outliner: Draw Gpencil modifiers in the tree

The outliner icon code had cases for grease pencil modifiers but the
modifiers did not actually draw.

Some icons are incorrect:
* Multiple Strokes
* Texture Mapping

Merge branch 'master' into soc-2020-outliner

Outliner: Draw collection icons in a row

Simulation: extract node tree parsing code to separate file

Simulation: separate code from node tree parsing and solver

Fix T78959: Show current frame indicator when interface is locked

When the playhead drawing moved to an overlay, a check was added to keep
it from drawing with a locked interface. This is necessary for some overlays,
but not this one, so this removes the check, making it the responsibility of
the editor.

A context function is added to make that check easier in the future.

Differential Revision: https://developer.blender.org/D8313

Support meshes with edges with or without polygons.

Transform: use GHASH_ITER when restoring customdata

Cleanup: Rename variables, use {} initialisation.

`{}` syntax would help catch when the C++ containers size() function
changes to `int64_t` since initialiser lists don't allow narrowing variables.

Specify that the strings are `_split`.

Cleanup: Removed incorrect `// namespace DEG` comment

No functional changes.

Merge branch 'master' into lanpr-under-gp

Merge branch 'master' into greasepencil-object

Merge branch 'master' into greasepencil-edit-curve