Blender Git Loki

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

* Made BKE_pbvh_trimesh_after_stroke join pbvh nodes as well as split
them.

Write a small design document. Committing it here
until I figure out how the new wiki works.

Fixed compile error due to renamed file.

Merge branch 'master' into xr-actions-D9124

Operators: Add modal_3d() and implement for box select

This follows the same logic as invoke_3d(). That is, we wrap an
operator's modal() with modal_3d() and project 3D controller coords to
2D mouse coords.

XR: Remove "replace existing" param from action bindings creation

Since action bindings are only created once at the beginning of an XR
session, overwriting all existing bindings will not be needed.

Merge remote-tracking branch 'origin/master' into lanpr-under-gp

LineArt: Memory debug info.

Merge branch 'master' into greasepencil-edit-curve

Merge branch 'master' into greasepencil-object

LineArt: Line cut reduction

cleanup

add some flags to detect geometry addition and removal

LineArt: default crease value changes to degrees.

Merge remote-tracking branch 'origin/master' into lanpr-under-gp

correct compile error following previous change

add a null pointer check

fixed various crashes

Created a new TMElemSet to replace GSet for tm_unique_verts and
tm_other_verts