Blender Git Loki

Add quadriflow remesher

Move file execute region back to C, fixing bugs

We moved this to Python too quickly, causing the following regressions:
* No auto completion for file names
* Additional handling not applied on changes, like automatic extension
appending (see file_filename_enter_handle)
* Red highlight missing when the file name already exists

Note that earlier (before the file browser redesign), this didn't use
the panel and layout code at all. So even if it's still not in Python,
at least it's integrated into regular panel management now.
OS-specific ordering of the open and cancel button is kept.

Fixes T69457.

Expose button UTF8 check in UI_interface.h

Used in following commit.

cleanup

better time sampling in mesh emitter

improve spacing of trail particles

take triangle areas into account

refactor triangle weight computation

compute barycentric weights more centrally

use Surface Info node instead of Collision Info

store surface velocities in surface context

refactor usage of MeshSurfaceContext

assert that the number of temporary buffers does not grow unbounded

cleanup

cleanup handling of emitter action contexts

support slicing ArrayRef with range

temporarily remove unnecessary emitter sockets

Merge branch 'master' into functions

Shading Modes: Material and Render Preview

This change implements the basics as described in {T68312} for the
shading modes.

* LookDev shading mode is renamed to Material Preview. It always uses Eevee as renderer, and is intended to provide a fast material preview suitable for texture painting, and texture and material setup.

* Rendered shading gains "Use Scene Lights" and "Use Scene World" options similar to current Material Preview. These will be enabled by default. When Use Scene World is turned off, HDRIs will be used for lighting instead. These options are available for EEVEE and Cycles.
* Renderers will be able to customize the shading settings panel and add additional settings.

Reviewed By: brecht, fclem

Differential Revision: https://developer.blender.org/D5612

Fix/cleanup error handling in paths generation for private ID data case.

When using new `rna_prepend_real_ID_path()`, caller have to handle the
NULL path case and decide whetehr this is a valid case or an error one.