add backoff support to the `Repeater`, and leverage it in Entities. has ...

...nice side effect of speeding up many of the tests which rely on this repeater, including SoftwareProcessSubclassTest which goes from 10s total to 1s total.
Agree, but don't like commented out code. Maybe change the comment to be more descriptive of not using `Math.pow` (because it sounds like a cheap comic book superhero) and place above line 174?