Add requirejs uniphil/js-tools

This commit roughly follows the getting started guide from RequireJS.

A single script tag in index.html loads requirejs and points it to the application entry-point, app.js.

app.js handles configuration for requirejs, and then simply requires the main module.

The paths config is used to specify the actual path to the jquery module, allowing other modules to simply require("jquery") by name.

main.js, finally, is the entry-point for application code. Later it might initialize a backbone View or something; for now it just requires jquery and a trivial test module, and calls a function from the module.