fix GH#343

fix GH#343

- An exec that ends right when the timeout expires is actually done
- when the timeout_detector finished, change the state of the action of
the ExecImpl that owns this detector to FAILED. This will trigger
on_state_change for the right action and solve the issue on energy
logging of this issue.
- Side effect, more instrumentation is displayed in another example of
a ptask with timeout.