Change to which WKB representations SpatialPolygons convert to
SpatialPolygons objects now convert to either WKB Polygons or WKB MultiPolygons
If each Polygons object in the SpatialPolygons object contains a single Polygon object with only one exterior boundary then convert to WKB Polygon, otherwise convert to WKB MultiPolygon
Previously SpatialPolygons were converted to WKB Polygon containing multiple rings