Major Description
At the moment the ChangeSet, which is populated by ChangeCollectorProvider (a Validator) during a commit, collects changed property names, as well as node name, node type and path of the parent (whereas parent for a property change is its node, while for a node change is actually its parent).
For improvements such as SLING-6163 it might be valuable to collect grand-parent changes (node name, node type and perhaps path) too. We could extend the ChangeSet with additional, explicit grand-parent sets (ie we should not mix them with the parent changes as that would lessen filtering rate)
