Blender Git Loki

GPencil: Fix brush icons

GPencil: Solve problem with Keymap missing

GPencil: Add versioning code for new tool

GPencil: More changes to keymaps and tools

GPencil: First steps to create a new Vertex Mode

Overlay Engine: Add Camera & Stereo Camera

This change a few thing:
- This fixes the toe-in convergence plane drawing issue.
- The volume wires are drawn without depth write to avoid Z-fighting.

Stretch To: implement a mode similar to Damped Track for rotation.

Most of the time Stretch To is used in actual rigs, like BlenRig
or Rigify, in combination with Damped Track to handle rotation
before the stretch, because it produces rotations more appropriate
for organic deformation, and doesn't flip because of internal
gimbal lock.

The prevalence of this pattern suggests that Stretch To should
support that kind of rotation directly as an option.

Differential Revision: https://developer.blender.org/D6134

Stretch To: clean up the math code in the implementation.

Combine computing `size` and normalizing the matrix, invert the
direction of `vec` to avoid negating it later, use `rescale_m4`
instead of matrix multiplication to scale the final result.

Differential Revision: https://developer.blender.org/D6134

Merge branch 'master' into asset-engine

Merge branch 'blender-v2.81-release'

Fix T70875: Library Override: Clicking an Library Overriden Object crashes Blender.

We also need to rebuild the whole collection/viewlayer object cache
thing when we relink an objector collection in a collection (since it
might be part of a view layer).

Again, usual disclaimer about how inneficient this is currently, needs a
serious refactor to only tag caches as dirty, and actually rebuild the
whole thing on access.

fix compile error

cleanup

make AttributesInfo non copy and non movable

rename GET_TYPE to CPP_TYPE

use monotonic allocator for network builder

use monotonic allocator for vtree generation

Cleanup: remove debugging prints for bpy.msgbus

rename functions2 to functions

remove old function system