allow accessing geometry by ref
allow accessing geometry by ref

tomhughes/mapnik,tomhughes/mapnik,tomhughes/mapnik,mapnik/mapnik,naturalatlas/mapnik,naturalatlas/mapnik,mapnik/mapnik,lightmare/mapnik,naturalatlas/mapnik,mapnik/mapnik,naturalatlas/mapnik,lightmare/mapnik,lightmare/mapnik,mapnik/mapnik,tomhughes/mapnik,lightmare/mapnik