Blender Git Loki

Fix various mistakes and forgotten bits in previous 'Views' adding commit.

Core API code shall now be mostly functional again.

Merge branch 'id_override_static' into asset-engine

Conflicts:
source/blender/makesdna/DNA_scene_types.h

Merge branch 'master' into id_override_static

Asset API: add Views.

This commit add new 'View' forth layer, below history one (Revision).

It also adds a real UUID for the asset repository (as usual, asset
engines not needing it can just set it to zeros), will make Amber's life
(and all multi-repositories engines) easier.

Also fix one or two issues found on the road.

Code builds and links datablocks from libraries in the 'old way'. Real
test will come when re-enabling Amber and adapting it to new API though.

Disable for now asset engines (in preparation of core code changes).

Merge branch 'id_override_static' into asset-engine

Merge branch 'master' into asset-engine

Merge branch 'master' into id_override_static

Add basic addition support to create new assets.

Again, very basic and limited, to be fleshed out later.

Working basic repository list.

Also, fixed uuids generation.

And finalized/added to UI operator to add a new, empty Amber repo in
current directory.

Merge branch 'id_override_static' into asset-engine

Merge branch 'master' into asset-engine

Merge branch 'master' into id_override_static

Merge branch 'id_override_static' into asset-engine

Conflicts:
source/blender/blenloader/intern/versioning_270.c

Merge branch 'master' into id_override_static

Add basic handling of 'bookmarks' of Amber repositories.

Still some glitches to fix (and missing features), but mostly working on
basic level.

Fix two bugs with Amber engine:

* Reported number of assets was -1 in list_dir callback, incorrect and
would loop endlessly in case of empty repo!

* Conversion from main asset classes to their propertygroup
representations was not clearing extra entries in proplists.

Merge branch 'id_override_static' into asset-engine

Merge branch 'master' into id_override_static

Moar WIP work towards editing Amber repo.

Adding skeleton for adding Amber repos, adding new assets... Not
finished yet, by far.