Blender Git Loki

Multires: Cleanup, naming

First of all, follow our naming convention to use module prefix.

Second of all, mesh is being created and is to be freed, we also
have convention for such function names.

Multires: Prevent crash when joining two multires objects

This only works thing around, just so we can unlock production here.
Joining objects of a different scale will not yet work correctly.

Proper fix is coming later (the code needs to be ported to new
Subdiv API).

Tool System: brushes are now categorized by tool

The toolbar now shows brush types, the brush selector now
only shows brushes matching the current tool type.

Details:

- Add's Paint.tool_slots (used by the toolbar).
- Removed custom grease pencil brush tool code.
- Bumped subversion.

See T57526 for details.

Fix assert setting fake user then removing

UI: Minor tweaks on User Preferences header.

* Move Save User Preferences to the right (matches file browser and quit prompt).
* Icons for Import/Export keyconfig
* Match order of install/reset of Themes section
* Rename "Install MatCap/HDRI" to "Add MatCap/HDRI"

UI: Rename Save User Settings operator to Save User Preferences.

The term Settings is not used anywhere, plus the menu entry and editor use the word Preferences.

UI Cycles: Open "Sampling" panel by default

Now that the Dimensions panel moved to Output, we can have the Sampling panel as the only one open by default.

UI: Sort panels in Render and Output

UI: tweak panels open by default

UI: add render output tab to properties editor

UI: Typo

Multi-Object-Mode: Edit curve draw (deselect all)

D3887 by @zazizizou

Multi-Object-Mode: Edit curve toggle cyclic

D3882 by @zazizizou

UI: Math Node Menu: Group and reorder

Change menu so that maths functions are grouped together more logically.

Cleanup: style

Fix bpy.app, sentinel was removed by accident

Eevee: Fix crash during Light cache baking

This was caused by some threading conflict.

Eevee: Opti: Irradiance: Remove sqrt and max on backface test

Did not have any impact in my tests and it saves some instructions.

UI: show messages and progress in topbar when status bar is collapsed.

UI: show blocking popup when auto execution of scripts is disabled.

This is important information, and it was easily missed at the top/bottom of
the screen.

Ref T57197.