Vary distanceFilter exponentially with speed, capped to 1000
Implementing setConfig, allowing reconfiguration of locationManager params desiredAccuracy, stationaryRadius, distanceFilter
Add a speed-acquisition buffer, where we crank-up the GPS power after engaging aggressive-tracking.  we sample a small number of location-updates before auto-calculating distanceFilter
Remove creating stationary-region in onPaceChange, since setPace will set the acquisition-process in motion.