[Geo API 643] Reshaped the polygon work so there's only one instance, and so there's a builder to make creating multi-ring polygons in a much more readable way. There's now an inconsistency in that GeoJson is the builder for most types, except polygon where it returns a builder. But the simplification in the code and the API is worth it.
[Geo API 643] Moved the GeoJSON shapes into their own classes.  This leaves a little tech debt on Point as this now exposes a method that should not be public, but this will be addressed when the geo querying piece is done.