note to fix helpers
enabling debug in dev config
tweaking api

challenge summary now shows difficulty and no longer the centroid which
made no sense. The challenges endpoint no longer falls back to a
default difficulty if none is given or set in the user preferences,
rather returns all difficulties and lets the client deal with it. Also,
repaired the contains functionality.
work around OSM home location lon bug

The lon in the home location stored in OSM can be greater than 180 or
less than -180 if the user panned across the -180 meridian in the map
setting their home location.