Blender Git Loki

Merge branch 'render-layers' of git.blender.org:blender into clay-engine

More Object mode work.

UI: temporary panels for layer/collections

bpy.ops.collections.* accessible outside collection editor

bpy.ops.collections.select()

When we introduce overrides we will extend it to have override_index,
and if it is -1, only set the collection

bpy.ops.collections.collection_new()

Remove old layers bitflag from viewport 3d header template

Let scene_collection and layer_collection to have the same fallback

Show Render Layer panel to clay engine.

Initial implementation of instancing

Add icon to collection panel

Fix logic for bpy.context.scene_collection

Unittest: refresh blender between tests

Mesh batch caches should not be stored in file

Properties Editor: Collection context

Collections Editor: populate header with operators

SceneCollection.objects.active_index (for user interface)

Collection related operators barebones

Those are the operators for the collections editor, and the collection property panel

RNA: collection override

bpy.context.layer_collection