Define a seperate JSHint configuration for NodeJS files
Summary: Currently, we assume that all JavaScript files are for use in a browser. This is not true for the NodeJS Aphlict server code. Split the current JSHint configuration into jshint-browser and jshint-node.
Test Plan: arc lint
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: Korvin, epriestley
Differential Revision: https://secure.phabricator.com/D11071