Add GeoIP_internal.h - missing from 12.04's libgeoip-dev

Implemented:
* geoip_database_info()
* geoip_db_avail()
* geoip_db_filename()
* geoip_db_get_all_info()
* geoip_id_by_name()
* geoip_region_name_by_code()
* geoip_time_zone_by_country_and_region()

Note:
- tests/014.phpt currently fails here and in the geoip PECL extension v1.0.8