Drop client side parsing of lat/lon parameters

The server always redirects these to a new style link with the
position in the hash, so we don't need to do it client side
Initial work on overpass based query API
Filter out nodes which are too far away
Improve styling of feature list
Show a message when no features are found
Increase search radius at lower zooms
Disable query feature tool below z14
Style feature in query mode to match browse mode
Consider addr:housename as a name source for features
Build and show partial geometries for relatons
Use POST for overpass queries
Make overpass server URL configurable
Abort any existing requests when starting new ones
Pivot areas to the underlying way or relation object