Blender Git Loki

Gizmo: start spin gizmo dragging

- Only respond to drag event, so placing the cursor is possible.
- Start off with zero rotation, dragging adjusts.

Cleanup: rename gizmo group data

Abbreviate to 'ggd', replacing manipulator reference.

Cleanup: use SCE_GIZMO_ prefix for gizmo_flag

Revert "Cleanup: use tuples in python according to feedback"

This reverts commit b1f0e4c2d673320085cd5e1c68f4f5f814bacede.

Sets are typically preferred for __contains__ checks
when order doesn't matter.

Fix T56817: Assert because of invalid framebuffer

Draw mode for hair follicles in edit mode.

Fix const-ness of hair primitive pointers for screen vertex callbacks.

Iterator functions and macros for hair primitives.

Fix driver expression bytecode validation crash if parsing fails.

Another NULL pointer access: nothing to validate if it already failed.

DPIX normal controlled line width

GP: Rename select group color to materials

Merge remote-tracking branch 'remotes/origin/blender2.8' into soc-2018-npr

# Conflicts:
# release/scripts/addons

Vertical line hack: tip point threshod fix and a condition branch.

Fix a crash when a driver expression evaluates to NaN.

The debug logging statement was accessing a NULL pointer.
Also happens in 2.79.

GP: Initialize new brush factors

Cleanup: use tuples in python according to feedback

Merge branch 'blender2.8' into greasepencil-object

Merge remote-tracking branch 'remotes/origin/blender2.8' into soc-2018-npr

# Conflicts:
# release/scripts/addons_contrib
# release/scripts/startup/bl_ui/properties_physics_cloth.py
# source/tools

Cleanup: use r_ prefix for return args

PyDoc: add gpu.shader

Also some syntax corrections.