Blender Git Loki

Merge branch 'master' into temp-openxr-blenderside

Ghost: Ghost-XR API to abstract away and access OpenXR functionality

Extends Ghost to include an abstraction for OpenXR, which I refer to as
Ghost-XR. Such an API is the base for the following commit, which introduces VR
support to Blender.

Main features:
* Simple and high-level interface for Blender specific code to call.
* Extensible for muliple graphics backends, currently OpenGL and a DirectX
compatibility layer are supported.
* Carefully designed error handling strategy allowing Blender to handle errors
gracefully and with useful error messages.
* OpenXR extension and API-layer management.
* OpenXR session management.
* Basic OpenXR event management.
* Debug utilities for Ghost-XR and OpenXR

For more information on this API, check
https://wiki.blender.org/wiki/Source/Interface/XR.

Reviewed by: Brecht Van Lommel

Differential Revision: https://developer.blender.org/D6188

Fix warning when compiling without WITH_XR_OPENXR

Change 'make update' back to use the master add-ons branch

Merge branch 'master' into greasepencil-object

Fix crash when rendering Eevee/Workbench while VR session runs

We have to set the main draw-manager mutex.

Also some related cleanup.

GPencil: Cleanup matrix multiplication

GPencil: Simplify Parent to Layer code and solve issue with bones

Merge branch 'soc-2019-openxr' into vr_scene_inspection

Merge branch 'temp-openxr-blenderside' into soc-2019-openxr

Revert changes to generalize 3D View Shading options button layout

Make it obvious that the DRW context getters are not for general use

Fix compile error when compiling with WITH_XR_OPENXR disabled (tm)

Always sync VR view shading with the 3D View the session was started in

Added a notifier subtype so that we can avoid unnecesarry updates of the
VR shading settings.
The VR session now needs to be invoked from a 3D View.

Volumes: cleaning / refactoring from code review

GPencil: Fix Snap cursor to Selected

It was using the original data and must use the evaluated data.

GPencil: Fix Parent layer not working

Merge branch 'master' into greasepencil-object

Merge branch 'master' into uuid-undo-experiments

Merge branch 'master' into uuid-undo-experiments