Refactoring to silex to more easily create multiple build monitors on one deployment.

New:

* Uses [Silex](http://silex.sensiolabs.org/) for PHP sever code, while still leaving some PHP code to be cleaned up ;)
* Changes URL patterns for scripts, XHR calls and so on to allow multiple build monitors while keeping it _RESTish_ AND easy to handle in silex.
* Still some TODOs, like providing index resource listing all available build monitors, ...