Point-based geography lookups

[tthibo]

A future feature we may want to explore: providing the ability to identify geographies for
a given lat/long point or address.

The idea was proposed on NICAR that we might build on the work TribApps has done on the Boundary Service. It would be a nice addition to Geomancer to allow point-based lookups of Census geographies, with geocoding a nice bit of sugar atop.

Would be a pretty heavy lift and a bit outside current scope, but I think it's at least worth a thought.