Integration with taxlot and/or building footprint sprites

[wstlabs]

Currently the app displays just a Yelp-style marker for a given property, geocoded to the street address (that is, to what the NYC Geoclient API gives us, which is the nearest point on the street grid).

This is fine, but we can do better -- OpenStreetMap can return a bright orange building outline sprite for most addresses, using a building footprints (shapefile) dataset apparently released in late 2013 (but since then apparently no longer available), which looks much classier. It also centers the map to the centroid of the building footprint (rather than to the street grid), which is also nice.

So that would be our ideal. If we can't easily get the building footprints, we should at least be able to generate taxlot sprites, which are part of the city's regular releases of MapPLUTO data.

Either way, there will be some caveats: (1) while conceptually the mapping from shapefile -> JSON -> SVG mapping should be straightforward, it's represented in terms of the city's surveyor grid (rather than lat/lon) - and there's more than just a 2D matrix transformation involved, last I checked.

And (2) coverage won't be 100%, so we'll need to default to the street grid mapping (like OSM does) for buildings that don't have footprints (using a suitable sprite).