Remove references to HTTPOK for consistency

 * HTTPOK is 200, but HTTPSuccess catches all 2xx anyway
Move yahoo/geonames url calculation into submit_url method
Simplify comparators with guard clause
Remove references to acts_as_mappable as this is external dependency

 * Not needed in:
   lat_lng.rb: as already next case checks respond_to which is enough
   mappable.rb: as this will return straight away in LatLng and only be used in acts_as_mappable anyway
     If someone includes Mappable without defining lat/lng_column_name
     They should define them or not call to_lat_lng
Simplify normalize methods
Update google geocoder options
Ensure MultiGeocoder dies if provider not defined

 * Ensures people rename google3 to google when upgrading