Tracking data changes

Tracking data changes is a complicated affair. It must match the RecyclerView behaviour as much as necessary to reconstitute the changes to the section graph, after being broken up into multiple layout passes. The basic approach at the moment is for the adapter to both notify SuperSLiM and the recycler view of data changes. When recycler view later notifies SuperSLiM of a change, that event must be matched up with the user action. This is necessary due to the inability to bundle information about the affected section in the notification to recycler view.