Rip out user location map

Inspired by @lxbarth's [diary post](http://www.openstreetmap.org/user/lxbarth/diary/20060), this pull request removes the UI elements for viewing/setting a user's home location.

The point here is that the "nearby users" as it is currently implemented is confusing to new users at best. I've heard numerous questions about what it's for at State of the Maps, and it has confused people signing up at my mapping parties.

If we want to keep it we should think about making it more useful and improving the user experience around setting/viewing the data.