Blender Git Loki

Workbench: Volume: Fix slice display opacity

GPU: Fix crash at startup

UI: move gpencil paint into topbar only layout

Tool properties were duplicating UI elements.

Cleanup: remove redundant checks

Cleanup: split object mode out of tool checks

Tool System: use enum for gp sculpt/weight paint

Fixes T57525

Cleanup: add arg to GP_EDITABLE_STROKES macro

Without this, we use arguments defined in the macro
making code hard to read.

Merge branch 'master' into blender2.8

Cleanup: use lowercase 2d/3d in function names

Cleanup: use doxy groups

Keymap: more more standard keys for select tools

This uses shift to extend, ctrl to de-select, both to intersect.

GP: box/lasso support for select-operations

This adds support for more adbvanced select operations
matching 3D view select operators.

Also de-duplicate box/lasso select code.

WM: default operators to replace selection

Tools now default to creating new selection.

Cleanup: use const args

Cleanup: remove unused source

Cleanup: use namedtuple for KeymapParams

Prefer immutable types where possible.

Merge branch 'master' into blender2.8

Eevee: Hide Sprite threshold as it is not implemented yet

Workbench: Volumes: Fix volumetrics step length calculation

Step size is now one voxel diagonal.
Fix T57678 Culling of smoke depending on view direction

Workbench: Volumes: Fix volumetrics rendering twices