Create global config that can be loaded from a local config.js file

[rufuspollock]

Global config would hold things like geonames user name.

This is also essential to production deployment where we need to set ES backend etc.

[rufuspollock]

See this good SO thread: http://stackoverflow.com/questions/5869216/how-to-store-node-js-deployment-settings-configuration-files and this specific library: https://github.com/flatiron/nconf