MaxMind provider

- IPv6
- `City/ISP/Org` service
- `Omni` service

This PR will be base on @lox PR #181 

![Screen Shot 2013-01-31 at 3 28 02 PM](https://f.cloud.github.com/assets/672421/114762/85f91f3c-6bb2-11e2-8e94-3cc567492bb1.png)