Create a standalone node.js script to generate geojson/topojson exports for various years

[danyx23]

The idea here is to have a tool so that you can run a command line script to create cartograms for a number of years. The output should be geojson or topojson depending on the command line flags.

Together with this it would be good to refactor the code a bit to pull out all the "business logic" and then have both the command line script as well as the web client would both pull those functions in.