Please add the possibility of loading data from other sources than file. [Patch Included]

[hhagblom]

diff.txt
diff_ignore_whitespace.txt

My use case is that I store the GeoIP database in a location on AWS S3 as I want it to be easy to change database in a cloud environment.

In the patches supplied I've opened up the API to load the database from any supplied string value (something that is already done internally)

[knoxcard]

https://github.com/runk/node-maxmind