Multiple Collections: SQL Changes

Conversion of existing db to revised schema for multiple collections,
including data fixes (for production) completed. Works against existing
db from production or elsewhere.

Next up: (Not yet implemented.) Fixes to PopulateDbFromJSON.cs so new db
can be created. Those fixes include:
* Implement default property as new parameter.
* Implement path property, including cleaning.
* Implement DisplayName -> SuperCollection cleaning.
* Also fix so pass in DisplayName, which is now unique.