Rather tricky work to enable new features to be created from drawn geometries, and their geometries preserved and shown as descs in the popups. This is now working. I've also fixed a bug related to the drawing of complex Polygons with cutouts; these now work correctly, and are distinct from MultiPolygons. Finally, I extracted a bunch of caption strings into a more flexible object which allows for addition of new languages and selects language based on the root lang attribute.