feature req: recursive call of task::invoke()

[gggeek]

I guess that having invoke() run only once for a given task is a good
thing, but I have a pakefile that is recursivevly building subitems
Without going the way of out-of-process re-execution, it would be nice
to have a way to execute again the same task (with different params of
course).
Right now I can call task::execute() by hand, but this forces me to
look for all task prerequisites and call execute() on them one by one
(and recurse on their prerequisites too), which is a bit of a chore.

[T-Moe]

I agree. There can be cases where it makes sense to use recursion on tasks or invoke tasks multiple times.