Updated code to Express js 4.0

Hello Antonio,

I have updated the Code to be compatible with Express js 4.0. I have updated

* _app.js -> Express components
* _package.json -> New dependencies
* routes/index.js -> Routes object
* views/index.html -> New UI (screenshot below)
* public/css/style.css -> New styles for new markup


![screen shot 2014-05-05 at 1 05 57 pm](https://cloud.githubusercontent.com/assets/2562992/2875853/f4143c8e-d427-11e3-891b-d396379818b6.png)

Request you to consider this pull request.

Thanks,
Arvind.