mechanisms -- thread cabinet additions

[Fred T. Hamster]

1. thread cabinet:
   1. method for cancelling a thread.
   2. method for starting a thread based on its id.
   3. thread pool needed primitive last hit
      1. what if the thread pool was supported partially by the object that is to be blanged with a thread activation reports on its last activation time?
      2. and then we also have, per object, an activation interval.
      3. this allows the thread pool to quickly dismiss guys that don't need to be handled yet.
      4. this is kind of like a lower level version of the scheduler.
      5. although the scheduler could be driven by a thread pool also.