Add mmdb file generation to output

[praemon]

It would be great to have an mmdb database file generated for the output IPs due to its compatibility and performance with many different IP parsing libraries.

Any thoughts on the feasibility of doing this in the building script?

https://blog.maxmind.com/2015/09/building-your-own-mmdb-database-for-fun-and-profit/

[splitice]

We do this internally with our lists so we know there are some problems.

1. Lack of standardidisation for a VPN field means for most this won't be useful.
2. The perl library for building mmdb's is hellishly slow