support for fusiontables without lat/lng columns, add samples folder

- added support for maps with geometry data
- added support for maps with only address data (no lat/lng columns)
- added default list/infobox format so that people don't have to do
anything extra
- added comparison helper for handlebars
- added different sample maps to help people with examples
- using US Health Center data as default (so that people outside SF can
experience nearby-location functionality)