Favor listeners over timers #2

Flug: The second priority in my mind has been the 'timer loop problem'--lots of the timer loops keep going even when that particular function, or Bombable itself, is de-selected in the menu. They use the old solution of re-setting the timer loop and then immediately exiting--but still use Nasal resources & cause the Nasal garbage collection issues. This should be replaced by more a listener-based solution. But the details of that solution need to be worked out in the best possible way and then--there are LOT of those timer loops in Bombable.