Too much to list...

It's been months since I committed this.  I've since used the core
Continuum UI code in a couple of other projects, where I added a bunch
of functionality.  I've done my best to roll that all back into the core
project, and additionally done some more work on the application itself.

The biggest obvious improvements are a smoother query experience,
implementation of date rendering, detection of the ArcGIS REST API data
source PK field, and beginnings of map support.