The previous implementation of sub-tasks did not work as expected: it
was possible to mark sub-tasks as completed before the parent task's
dependencies were satisfied. In addition, it was impossible to retrieve
a task's path from the database without running a recursive query.
Full paths to sub-tasks added to views, since it is now possible to
obtain them.
A description field has been added to items in the database, form fields
have been added to both item creation and modification. Removed some
French text that was still around.
This initial import is a heavily modified version of the code I had
here, as Arse was modified for other purposes in the meantime and the
application no longer worked with it.
In addition:
* I did not import the user management part yet,
* task dependencies are supported in-base, but there is no interface
for that yet.
