[Test] Tornado web server

Tornado is another lightweight Python web server (http://www.tornadoweb.org/).
Currently, we are using CherryPy (http://www.cherrypy.org/).

CherryPy seems to be a very good framework and Tornado too.
This branch is just here to discover the Tornado functionalities and to choose the best framework for us.

## Please do not merge this pull request!