Blender Git Loki

Implement support for Append objects in Blender 2.8

Note for users
==============

The active_layer option used for the filebrowser operators is now called
active_collection.

If there is no collections in the scenelayer or if this option is not selected
we automatically create a new collection for the new objects.

This is the same behaviour of trying to add a new object when there is
no collection.

Note for developers
===================

For those cases I moved the object user count handling from readfile to
the scene collection system. It's working fine for those, but we still
need to re-visit this for Add objects, and Duplicate - In those cases
the usercount is 2 when it should be 1.

Reviewers: mont29, sergey

Differential Revision: https://developer.blender.org/D2686

Rename BKE_layer_collection_active > BKE_layer_collection_get_active

Move util function to add new scene collection when active is not available from object to layer

Depsgraph iterator: Add assert for bases not yet evaluated

Gawain: move convert_prim_type_to_gl to private API

Fix removing texface layer

Merge branch 'master' into blender2.8

Fix freeing all custom-data layers

Would crash when the active index was out of range,
since there is no reason to use the active layer when freeing all,
free the first instead.

Fix T50908: Motion Tracker ignored grease pencil mask

This feature got lost with new auto-track API,

Added it back by extending frame accessor class. This isn't really
a frame thing, but we don't have other type of accessor here.

Surely, we can use old-style API here and pass mask via region
tracker options for this particular case, but then it becomes much
less obvious how real auto-tracker will access this mask with old
style API.

So seems we do need an accessor for such data, just matter of
finding better place than frame accessor.

Fix integer overflows in meshcache modifier.

Differential Revision: https://developer.blender.org/D2688

Fix uninit shading group in object mode particles

Remove MTexPoly layers

Remove default shading groups from eevee

Fix indentation in clay_engine.c

Merge branch 'master' into blender2.8

Fix T51609: Bake Texture, Margin crashing Blender

Integer overflow in margin filter code.

Depsgraph: Rename DAG > DEG functions from depsgraph_query.cc

Fix T51350: 2D curve normals flip when deformed

Deforming 2D curves & text with modifiers/shape-keys
could flip the normals.

Now check the back-facing flag instead of `z < 0`.

Fix T51287: Matrix.lerp fails w/ shear

Use interp_m4_m4m4 (wraps Eigen),
`MATH_STANDALONE` will need to be updated to support this.

Fix GPencil depth checks

Regression in 195d0fba