Subroute navigation

Oh interesting. Because the parent may be active, but we are not, this avoids inheriting those values. Certainly makes the logic here way uglier though (zeroing twice, blah!)

I wonder if we should cut a corner and just delete here, to avoid the zero-on-read step above. <rationalization>Plus, the values inherited from parents seem somewhat reasonable to inherit, even when inactive. Less binding flippage when routes transition state, too.</rationalization>