Blender Git Loki

COW Fix: Material property update callbacks need to tag depsgraph for COW updates

Otherwise, trying to change color/material properties of EEVEE materials
that have been keyframed doesn't work until a new keyframe has been inserted.

NOTE: There's still some wonkiness if you edit more than one keyframed value
before keyframing (i.e. the other unkeyed value temporarily gets reset). But
that's more of a general COW+animation issue.