CSHARP-685: Add object model for GeoJson values.
CSHARP-685: Use "point" and "position" more precisely following the GeoJson spec.
CSHARP-685: Added some missing serializers.
CSHARP-685: Added more missing serializers.
CSHARP-686: Added some unit tests and fixed some bugs.
CSHARP-685: Alternative technique for handling how GeoJson flattens bounding boxes.
CSHARP-685: Even simpler implementation of bounding box serialization.
CSHARP-685: Reverting to the original approach of handling bounding box serialization in order to avoid adding otherwise unnecessary constructors to the TCoordinates implementation and tricky delegate construction using reflection.
CSHARP-685: Finished up GeoJson helper class. Added remaining unit tests. Some refactoring and bug fixing.
CSHARP-685: Rewrote TestGeoSphericalIndex from using raw BsonDocument to using the GeoJson object model.