Blender Git Loki

GPUBatch: Change preset managment system.

Now use a list of preset batches with a function to add new ones to this
list.

This removes the need of new functions all over the place to reset/exit.

GPUShader: Add 2D Nodelink shader.

Special shader to draw nodelinks for the node editor.

We only pass bezier points to the GPU and vertex position is handled inside
the vertex shader.
The arrow is also part of the batch to avoid separate drawcalls for it.

We still draw 2 pass one for shadow and one for the link color on top.

One variation to draw instances of theses links so that we only do one
drawcall.

Undo: split text undo steps out of the data-block

This moves undo storage into a separate struct which is passed
in from the undo system.

Undo System: return undo step from undo push init

Also improve logging

Logging: use -1 log level to log all levels

ED_undo: use logging

Fix crash w/ empty text undo operations

Fix Cycles motion blur and engine.frame_set() not working.

Depsgraph: Fix/workaround crash with animation and drivers and CoW

The issue was caused by component tag forcing CoW component to be run,
without actually flushing changes down the road from the CoW operation.

In a way, this is what we want: we do want CoW to run on changes, but
we don't want tiny change forcing full datablock update.

This commit makes it so order of updates is all correct, but the bigger
issue is still open: what parts of datablock CoW should be updating?

Now it's possible to open spring file and play around.

Gawain: Make removing batches more thread safe

The issue was mainly visible when copy-on-write was enabled. This was forcing
lots of meshes to be freed from multiple thread, causing all sorts of race
conditions in Gawain's VAO code.

OpenGL resources seems already to be doing deferred deletion, need to do the
same for CPU side arrays.

Merge branch 'master' into blender2.8

Conflicts:
source/blender/blenkernel/BKE_object.h

Fix modifier freeing code re. ID refcounting.

Free code should not handle ID refcounting at all. This has to be done
at higher level, since in some case we want to free (temp) data that
actually did not refcount at all its IDs.

This change seems to be working OK, but as usual in that area, only
lots of testing in real-case situation will say whether there are some
hidden bugs or not.

Fix Cycles particle info node not working.

Depsgraph: Cleanup, reduce indentation level

Merge branch 'master' into blender2.8

Depsgraph: Make sure textures used by modifiers are in the graph

Proper fix for T54337

Accidentally checked the wrong variable in fa01a1738bd1e3a6750ff.

Fix undefined workspace in UI script

Fix Eevee crash with generated coordinates on non-objects.

Cleanup: simplify fix for T53497, this part is not strictly needed.