Support for newer versions of Ubuntu

[JCBauza]

I read everything is tested for 12.04LTS, but would be nice if it could support the latest versions particularly the ability to use cache purge with NginX.

[rahul286]

We use LTS only for ourself. So LTS will be supported first.

Once we are done with adding few features that are critical to our day-to-day usage, we will focus on adding support for Ubuntu 13.x and Debian 6/7.

In meantime, if you manage to tweak easyengine on your end, feel free to send a pull request.

[rahul286]

Will be solved after #130