Add fields for min/max lat/lon per geo
Load census tracts in a particular view port
Load as you scroll
Underscorify + docs
Update test fixtures
Test rect-specific tract loading
Respect the filter -- remove duplicate calls
Merge upstream
Comments on the afterLoad function
Don't pass around the four individual bounds; just pass a bounds object
Use CDN for underscore
Merge pull request #19 from cmc333333/shapes-in-viewport

Load only census tracts in the viewport