CommonAPI DBus mock object generator

[zayfod]

The idea is to create a new module and corresponding command-line tool that can take a Franca IDL model and generate CommonAPI DBus mock objects, e.g. based on pythond-dbus that can later be used in automated tests, based on Python's unittest methodology.

This is a stretch goal, currently out of the scope of pyfranca. If there is interest hough, help is always welcome! :)