Major Description
Working with Polygon is a bit tricky today because you typically
must use an external dependency to convert e.g. a GeoJSON string into
Lucene's Polygon class ... I think this is a weakness in our API, and
it clearly confuses users: http://markmail.org/thread/mpge4wqo7cfqm4i5
So I created a simplistic GeoJSON parser to extract a single Polygon
or MultiPolygon from a GeoJSON string, without any dependencies. The
parser only handles the various ways that a single Polygon or
MultiPolygon can appear in a GeoJSON string, and throws an exception
otherwise.