Merge: Admin interface for Benitlux and fixes

This PR adds a RESTful admin interface to the Benitlux server. This interface is used to trigger sending out the daily menu notifications from an external program / cron.

As a fix to the diff showing everything as new on the menu, the server now standardizes the received dates to the format expected by SQLite. There is also a small fix to the library used by the code generated by nitrestful to correctly check for errors.

Pull-Request: #2090
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>

diff --cc contrib/benitlux/src/benitlux_controller.nit
Simple merge