Fixed sorting/selection, toolbars...

I noticed this morning that sorting the DataGrid with rows selected
would cause it to get the set of rows that are actually selected wrong
after it got done sorting.

Implementing use of the DataView fixed this, and also supercedes the
RecordCollectionData.  I've left that in the project for now, just in
case, but it should be removed at some point.

Also, began work on the toolbar, which looks pretty good.