Added protractor support

Protractor should now be working through the [grunt-protractor-runner](https://github.com/teerapap/grunt-protractor-runner) plugin. Protractor uses WebDriver which is installed as a post-install hook when `npm install` is run. I've only tested this on Ubuntu 12.04 so it would be appreciated if this could be tested on Windows / Mac.

To get this working, a couple of tweaks have been made to the `gruntfile` and the `server/config/express.js` files, most notably ensuring that the express server is started with the correct config in test mode, so that the angular files are served for protractor to use.

Protractor 'spec' files have been given a `.e2e.js` file extension, which is used throughout to identify the protractor files to be loaded / not loaded as appropriate.