Split requirejs config and main

Summary:
Split requirejs config/Init.js into Main.js and Config.js
Makes it easier to reuse the config in tests, and generally tidier

Test Plan:
- Fire up the UI and check everything still loads
- Run `grunt build:js` and make sure it works
- Switch to production mode and check the built js works

Reviewers: dkobia, eyedol, shadowhand

Reviewed By: shadowhand

Differential Revision: https://phabricator.ushahidi.com/D217