This function will return different results based on the data used and based
on how the GeoIP module is configured.
If a region database is used, it may return the country code, region code,
city name, area code, latitude, longitude and postal code of the visitor.
Alternatively, only the country code may be returned for another database.
If your HTTP server is not configured to include all GeoIP information, some
information will not be available to Piwik.