Forked from https://svn.openstreetmap.org/applications/utils/import/bulkupload/?p=34681
Also see https://github.com/grigory-rechistov/osm-bulk-upload
Two important gotchas when using:
- All ids have to be unique. You can't have the same id in different classes of OSM objects. Use the osmium renumber utility beforehand.
- Smart sort does not know about relations refering to other relations so won't know which order to put them in.