Add Phusion Passenger

This pull request adds Phusion Passenger. It is an advanced process manager that's like a combination of Init, PM2, Cluster and Nginx combined in a single thing. This makes deployment a lot easier and significantly reduces the number of moving parts.

Many people seem to like it:

https://twitter.com/ranzwertig/status/510392698776616960
https://twitter.com/NinjaTux2K/status/510334670673027072
https://twitter.com/kidkarolis/statuses/427419356637581313
https://twitter.com/allaire/statuses/452475962614349825
https://twitter.com/mukeshsoni/status/432049357378961408

More info:

 * https://www.phusionpassenger.com/node_weekly
 * https://github.com/phusion/passenger/wiki/Phusion-Passenger:-Node.js-tutorial