New package wrapping oschwald/geoip2-golang to open MaxMind .mmdb databases
directly out of cached <edition>_LATEST.tar.gz files (no Transform, no
intermediate extracted mmdb). ParseConf reads MaxMind's GeoIP.conf format
for AccountID + LicenseKey. Includes geoip-update CLI, integration test,
and a copy of the MMDB binary format spec.
