enable other map projections than the Mercator

[clhenrick]

Incorporate a functionality to let users create world maps that use other types of map projections such as the Robinson, Winkel III, Orthographic, etc. D3.JS has a good list but not sure how easy it would be to incorporate them into this tool.

[mikefowler]

As mentioned to @clhenrick offline, I'd like to implement additional projections as separate includes that would either override the default or be incorporated into a build tool so that devs can include only the projections they need.