add initial "proxy" interior rings implementation
add initial "proxy" interior rings implementation

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