Python/Depsgraph: bpy.data.*.is_updated now detects add/remove of any datablock.
Previously this only worked for some datablocks relevant to rendering, now it
can be used to detect if any type of datablock was added or removed (but not
yet to detect if it was modified, we need many more depsgraph tags for that).
Most of the changes are some function parameter changes, the important parts
are the DAG_id_type_tag calls.
Reviewed By: sergey, brecht
Differential Revision: https://developer.blender.org/D195