Blender Git Loki

UI: Improve brush toolbar

This is a temp solution to show all brushes and sort by use, not alphabetical.

This will be replace when new tool bar system is in place.

Fix duplication error for Brushes

This produced an error when create a new brush and a memory leak when closed Blender.

Provide a switch to enable chaining or not.

Merge branch 'blender2.8' into greasepencil-object

Chain support line types and levels.
Still bugs in chaining, hard to find, but results good enough in most of the conditions.

Clenup: Remove old unused code

Merge branch 'blender2.8' into greasepencil-object

Merge and changed GWN APIs into GPU ones.

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

# Conflicts:
# release/scripts/startup/bl_ui/space_view3d.py
# source/blender/draw/intern/draw_manager.c

Merge branch 'blender2.8' into greasepencil-object

Merge branch 'blender2.8' into greasepencil-object

Merge branch 'blender2.8' into greasepencil-object

Revert temp fix for materials preview

Merge branch 'blender2.8' into greasepencil-object

Conflicts:
source/blender/editors/render/render_preview.c

Merge branch 'blender2.8' into greasepencil-object

Fix segment fault with material previews

This fix solves the issue with multiple previews at the same time. Maybe there wll be a more general solutions in render preview module, but we need keep the system running.

Fix render triangle size increment error.

Fix fileread error again.

Fix taper on segment_count==1 situation

Fix detail reducing bugs