Add migration generator for geolite city database.
Add rake task for loading MaxMind data.
Add local DB support for :maxmind_local lookup.
Fix incorrect column name.
Add MaxmindDatabase module.

Also split single rake task into several.
Unzip archive in platform-independent fashion.
Remove unnecessary condition from query.
Rename tables.

Need increased specificity to support other MaxMind packages.
Only require 'zip' if necessary.
Document :maxmind_local usage.
Add support for Geolite Country local SQL DB.
Support DBs other than MySQL (:maxmind_local).