add .em files to watch:scripts
Add default config setup.

Allows specifying configuration in the following files:

* `config/environment.js` - This is loaded in all enviroments.
* `config/environments/production.js` - This is loaded when
  building with `grunt dist`.
* `config/environments/development.js` - This is loaded when
  building a normal development server (via `grunt server` generally).
* `config/environments/test.js` - This is loaded when running tests via
  either browsing to `/tests` URL or running via karma.
Don't destroy global config object

This will encourage people not to destory their window.ENV object by
reassigning it a completely new value.

The environemnt specific files should load after `environemnt.js` has
loaded. This way the values assigned to `window.ENV` in those
environment specific files can overwrite any defaults set in
`environment.js`

I have also cleaned up the comments somewhat and included a simple
example of setting a config value.
Bump ic-ajax

Bump to the version of ic-ajax that distinguishes
between ic.ajax and ic.ajax.raw