Avoid NPEs if an OSMWithTags doesn't have tags
Handle OSM multipolygons which have tags on an outer member

* OpenStreetMapContentHandlers are modified to load relations+way
  in the first phase (ways are loaded again in the second phase).
* The method names called after each phase of OSM loading are renamed
  to be consistent.
Remove relation->way copying code for multipolygons

It isn't needed since areas are processed separately from "linear" ways.
Add static bike rental stations (from OSM) to a BikeRentalStationService
so that /ws/bike_rental returns the stations
Update Hungarian translations