use almond module loader

This allows us to use other AMD or ES6->AMD
modules outside of the ember application objects.

For example, to use the moment date library:

1. Add it to bower.json and bower install
2. Add it to index.html with other vendor scripts
   (we should change this too)
3. In your code `import moment from 'moment';`

Note: renamed loader.js to resolver.js because
it doesn't do the loading anymore, just the
resolving.