Add ocean-centric arrangement and an icosahedron net

[MattBlissett]

This page says "Fuller explored more than 25 different useful configurations of the Dymaxion Air-Ocean World Map", but I can't find them. This PR implements the ocean example shown on Wikipedia, and a basic icosohedral net.

There's also some SVG templates for the net version to allow easy printing:

(Second one shows data from GBIF: 0 and 1)

I don't often use Python, so feel free to ignore or reimplement differently.

[Teque5]

FYI I'm not ignoring this PR; I just haven't had time to digest it yet. I'll review your changes soon.