[TW-122] Allow creation of a recurring task / sub-task pair

_Jennifer Cormier on 2012-02-25T00:53:44Z says:_

I would like to create a recurring task (T) with a sub-task (S). I can make task T depend on the first instance of sub-task S (S-1). But then when a new instances of task T are created, they all depend on S-1, rather than later instances.

i.e. I'd like the tasks to work as follows

1 (hidden) recur:weekly due:Thursday -- Draft report

2 (visible) recur:weekly due:02/09/2012 -- Draft report

3 (hidden) recur:weekly due:Friday -- Finalize report

4 (visible) recur:weekly due:02/10/2012 dep:2 -- Finalize report

5 (visible) recur:weekly due:02/16/2012 -- Draft report

6 (visible) recur:weekly due:02/17/2012 dep:5 -- Finalize report

But task 6 depends on task 2 unless I manually modify task 6 to depend on task 5 instead. And such a manual modification needs to be made each week for the new tasks generated.

It's not difficult to come up with scenarios in which such a feature would be quite useful. E.g. a 5 step process that needs to be done monthly, such as: draft report, submit for review, update based on feedback, have it signed, submit.