[Fix bug 976330] - Add location entering UI to edit profile

Will need a valid Mapbox ID added to the settings

If running locally, add this to local.py:

CSP_DEFAULT_SRC += ('http://*.mapbox.com',)

There are notes in the README about converting existing data and what will need to be done afterward.
There's an attempt to make searching on place names continue to work, and privacy settings for city, region, and country name, but we didn't have time to test those change at all.

(above c/p from original PR)