Export

- [x] TextBlock
- [x] Button
- [x] USMap (Kristian) 
- [x] Glyphs (Hannah)
- [x] Hook up USMap and Glyphs to QueryAction `onChange` functions (Sean)
- [x] Property Actions
- [x] Property Action rerenders USMap and Glyph. (Sean)
- [x] If a Property Action changes a dataSet property, transfer any `onChange` functions for this widget from the old dataset to the new one. (Sean)
- [x] Nested Property Actions (Sean)
- [x] Query Actions (Keith - to start)
- [x] Property Actions with templating (Steve)
- [x] Query Actions with templating (Make sure the required functions are exported even when there are no property actions.
- [x] Events
- [x] Google Analytics (Kristian) - ** Needs to be fully tested **
- [x] Data Source (Keith)
- [x] Data Subsets (Keith - to start)
- [x] Handle visible property for widgets, including not rendering map and glyphs if visible is false.
- [x] Make sure all properties of button and textblock are set initially with CSS and updated with actions. (Sean)
- [x] Get auto-actions working for USMap and Glyphs.