Blender Git Loki

Depsgraph: Fix missing animation update when tweaking fcurves in graph editor

Not totally happy with this solution, mainly:

- It's a bit weird to explicitly tag ID for update when updating animation data,
thinking maybe we can have function like DAG_anim_data_tag_update(). But it is
also a bit tricky to get back from animation data to ID it seems.

- Re-scheduling time update tags is not supported at this moment. This means if
both relations are tagged for update and animation data is tagged for update
the animation update will be missing.

Anyway, it's an interesting issue and think it's good starting patch for it.