Contacts geolocation API to convert partner addresses into GPS coordinates.
You can configure in General Settings the default provider of the geolocation API service.
A method _call_<service> should be implemented in object base.geocoder that accepts an address string as parameter and return (latitude, longitude) tuple for this to work.
If no default provider is set, the first one will be used by default.
An optional method _geo_query_address_<service> which takes address fields as parameters can be defined to encode the query string for the provider.