Reduce load and hopefully fix optimized script.

Changed timing from 50ms to 250ms to reduce cpu. Also changed so that if current gauge value is equal to DecayingAccumulator value then no need to refresh the gauge.

I think it would be a more efficient solution is if you could update the DecayingAccumulator to allow a callback for when a nudges occur and expose the current decay rate in milliseconds. Then I could set the animation speed on the Raphael gauge to change at that rate and only update on nudges.