The tests were using a fake timer that only ticked when the test cases
told it to, so it would only be correctly testing the
BoundedFrequencyRunner functionality if the test cases made it tick
whenever the BFR timer was supposed to expire, and didn't make it tick
at any other time. But they didn't do that. Fix it to tick
automatically at the correct times, and update the test cases
accordingly (including adding a new helper method for asserting that
the runner did nothing in cases when it's expected to have done
nothing).
Also fix two unrelated minor bugs in fakeTimer.