Blender Git Loki

Revert hack making linked virtual datablock editables.

Essentially, this reverts most ID_IS_LINKED_DATABLOCK() checks to
ID_IS_LINKED() one.

Idea of making virtual linked IDs editable was nice as a temp hack to do
quick experiment, but was never intended as final solution, correct way
to do that is to use static override, will be implemented soon.

Note that virtual library/virtually linked ID concept remains, it's
mandatory to handle mere files as assets (and potentially other, more
advanced cases in the future).

Optimize Fast Drawing memory management

Various RNA fixes (noticed while adding palette slot support)

* Added missing define for GP Object datatype in rna_Object_data_typef
* Improved a few descriptions/comments

Fixes for various problems with the linked-datablock handling code for GP features

* The new "Scene->gp_object" field was not being relinked in various places

* The "bGPDstroke->palette" relinking calls were missing the standard "id.lib" args

* "bGPDlayer->parent" should be handled in lib_link_gpencil() not direct_link_gpencil(),
It was also not handled in the expand_doit()

Code Cleanup - Some leftover cruft/reshuffling/formatting

Palette Slots - File IO and Basic RNA support

Palettes Slots - Fix incomplete DNA changes from previous commit

Fix T52574: make Cycles rendered tile counter more clear.

Differential Revision: https://developer.blender.org/D2853

Cycles: reduce subsurface stack memory usage.

This is done by storing only a subset of PathRadiance, and by storing
direct light immediately in the main PathRadiance. Saves about 10% of
CUDA stack memory, and simplifies subsurface indirect ray code.

Fix T52086: Graph editor "normalize" drag errors for integers

Merge branch 'master' into blender2.8

Fix T52932: Driver with target of custom property from scene fails to update

Note that this is only supported in new depsgraph.

Merge branch 'master' into blender2.8

Merge branch 'blender2.8' into greasepencil-object

Curves: Fix wrong bitset being checked against CYCLIC bit flag

Based on report from Talos Security Advisory.

Merge branch 'master' into soc-2016-pbvh-painting

Adding paint brushes crashes w/ linked libs

While we could skip this for linked files,
convention so far is to only update startup.

Cleanup: switch fall-through warning

CMake: move MSVC warnings to central location

Missed in last merge from master

Local changes built, but merge-commit needed amending.