Google instead of Yahoo to fetch lat/lng

Dealer locator was not working properly because changes in dealers would
overwrite lat/lng with empty values.

Found a statement from Yahoo.

We are shutting down this service on September 13, 2011. We suggest
using maps from our partner Nokia. Please visit developer.here.net for
more information.

Changed the code to use the Google Maps API and fetch JSON information
with Javascript instead of requesting another PHP file to make the
actual request.