Blender Git Loki

Minor cleanup in sequencer_draw.c

Minor style cleanup, and also replaced manual checker drawing by a call
to `imm_draw_checker_box`.

Part of T49043

OpenGL immediate mode: clip_draw.c

Part of T49043

Add imm_draw_checker_box function

This replaces `fdrawcheckerboard` in drawing a standard gray
checkerboard for alpha backgrounds.

Doversion: merge collection engine properties

This is a more complex approach, which makes me really want to use
IDProperty instead (assuming we handle their merging nicely).

In fact I would expect this to happen in readfile.c, not during
doversion, but I can revert this later.

For now this allow for demo files saved with 2.8 to keep working even
after we add/remove engine settings properties.

The values are merged. There is no purge though, so
old CollectionEngineSettings and CollectionEngineProperty will live
forever (for the time being).

Doversion: reset layer collection properties when needed

This prevents crashes when a file was saved with 2.8, but a new
engine settings property was created.

In those cases any previous collection settings are wiped out. We can do
an elegant merge soon.

Layer: add name to mode engines

UI: Move 'relations extras' right below 'relations'

Differential Revision: https://developer.blender.org/D2218

Fix T50687: Cycles baking time estimate and progress bar doesn't work / progress when baking with high samples

Clay Engine: Fix Cursor too bold

Clay Engine: Correct Mesh Normals

Clay Engine: Fix Axis Name shader

Outliner collection operators: linking!

Register test for mesh.split_faces()

Outliner collection operators, all but collection link

Note: It may be missing a notifier to prevent Outliner from crashing
when deleting collections.

Clay Engine: Hidden wire

Clay Engine: Wire and Backface cull collection settings.

Clay Engine: Fix grid not showing.

Faces split: Don't leave CD_NORMAL after split

This is supposed to be a temporary layer.

If someone needs loop normals after split it should explicitly
ask for that.

Cyctes tests: Commit blender.git side changes

CDDM Copy: Only tag data layers dirty if we ignored tessellation data

This solves assert failure in CustomData_from_bmeshpoly() happening with
broom.blend file from barber shop SVN.