The project is now directly added to the context local g object, and injected on the fly into the urls that need it.
This commits also add ideas found while reading the flask documentation. The project can be enhanced in many ways, some ideas are stated there.
* Ask confirmation before deleting an user
* Display the form when clicking on the add bill button
* Only show the delete button (for users) on mouse over.
This commit adds:
* support for projects (creation not yet finished)
* an authentication mechanism
* bugs (basically all the features are not working anymore)