Poll faster when idle

[digitaltrails]

If no methods or properties have been set in the last N seconds, poll detect faster, perhaps every 10 seconds.

[digitaltrails]

D-Bus services are essentially always serialised (no parallel execution). Because there is no parallel execution, perhaps just set the default poll interval to something like 10 seconds and don't worry about varying the interval.

But maybe we need to be cautious given the varied hardware out there.