Blender Git Loki

Assorted Cleanup/Fixes

Annotations: Dynamically updating layer-color preview icons + "Active Note" enum

This adds a new enum with dynamically-generated icons to show previews
for the icons associated with each GP layer used for annotations. This
enum is used as part of the UI for annotations (specifically, in the
topbar settings for the active tool), making it easier for users to
see what color strokes drawn using the active note/layer will look like.

I ended up needing to create a new icon type in BKE_icons.h so that
we can store references to the layer/color used.

Known issues:
* The icon seems a bit too big, and would look a bit nicer with
rounded corners. But there are too many issues with the UI roundbox
functions (e.g. _aa() makes colors too dark, and non-aa versions look
too rough).

* Changing layer colors doesn't redraw the icons. A manual refresh
(by mousing over the widget) is needed.

Cleanup: Whitespace

Cleanup: Remove need to set colors on each and every annotation point when drawing

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

Fix duplicate Brush in tool bar

Merge branch 'blender2.8' into greasepencil-object

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