Blender Git Loki

Support both factory and user startup for templates

This supports a split between factory and user startups for templates
(as we have for default startup.blend)

OpenGL: `paint_cursor` port to immediate mode (Part 1)

Part of T49043

Object Mode Engine: New grid drawing.

Move the grid drawing to the Object mode engine and implement a new infinite grid.
Everything is done but it needs better parameters to be intuitive.

Draw Module: Move the Global Ubo block definition to it's own file.

fix redundant assignment

Thanks clang for the warning.

OpenGL: use new API for persp & ortho projection

Still using legacy GL within the GPU library itself, but we'll be able to switch soon.

Part of T49450

Merge branch 'master' into app-templates

Cleanup: remove BLI_getlastdir

Replace with BLI_path_name_at_index

Pydoc: Change Wikipedia links and grammar in mathutils matrix code

Merge branch 'master' into app-templates

OpenGL: load projection matrix with new API

New API does not share legacy OpenGL's concept of matrix modes.

Part of T49450

Merge branch 'master' into id_override_static

OpenGL: fix new projection matrix API

Now using the correct GL enum.
Part of T49450

Cleanup/optimization: Simplify some usages of uiItemFullO/_ptr, avoid multiple search of same op.

Cleanup: ignore open-blend as startup/prefs basis

No reason startup/prefs would ever be blend-file relative.

Layers Unittesting pep8: 2/2 (manual changes)

Layers Unittesting pep8: 1/2 (mass changes)

Merge remote-tracking branch 'origin/blender2.8' into temp-depsgraph-layers

Layer Unittesting: pep8 2/2

Mass replacing the common code of all tests

```
echo "Fixing $1"

ed "$1" <<'EOF'
1,/Testing/d
i

from render_layer_common import *
import unittest
import os
import sys

sys.path.append(os.path.dirname(__file__))

.
w
q
EOF
```

Using line-width of 120

Layer Unittesting: pep8 1/2

Manual corrections, using line-width of 120