+ removed multiple geometry typedefs
+ use geometry_type
+ revert to storing vertices in vector_vertex
(previous implementation using std::vector was
fragmenting heap causing performance issues with large geometries)
+ FIXME: hit_test is broken!
(FIXME : label_spacing is still, too slow!!)
2. Re-use some agg objects.
3. placement_finder cleanups!
4. Added support for 'building_symbolizer' - extruded polygons