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.
In addition to normal dependencies, the application now supports
sub-tasks. Sub-tasks can be added into any existing task (including
other sub-tasks, Inception-style).
Dependencies can only be added between global tasks, or between
sub-tasks of the same task. It is no longer possible to mark a task as
finished if it has incomplete sub-tasks, and conversedly, it is not
possible to reactivate a sub-task if its parent is marked as completed.
A pair of buttons allowing tasks to be moved up and down in the task
hierarachy have been added.
Removed duplicate code in task lists views (now using a single class
with constructor parameters). Added specific display for assigned tasks
that have missing dependencies.
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.
