Blender Git Loki

Fix T46329: scene_update_{pre,post} doc needs clarification

The documentation for the bpy.app.handlers.scene_update_{pre,post}
handlers states that they're called "on updating the scenes data".
However, they're called even when the data hasn't changed. Of course
such handlers are useful, but the documentation should reflect the
current behaviour.

Reviewers: mont29, sergey

Subscribers: Blendify

Maniphest Tasks: T46329

Differential Revision: https://developer.blender.org/D1535