We started to move to Open Street Maps (OSM) and one simple change was
to show OSM tiles on top of the current Google Maps functionality. This
hybrid use violates Google's terms and conditions though and I'm
reverting it here (basically reverting daa5b00a2).
Another branch of work was already started to use OSM without Google
functionality and it's available behind a feature toggle. We can
continue that work in our own time without a license violation. This
change is only changing the tiles, the look of the map and doesn't touch
any functionality which was always provided by Google Maps.
