currentsensenode: Update for DigiSpark

* Removed All debugging stuff
* Removed THRESHOLDLIMIT, thresholdPin, statusLEDPin
* Removed TimedEvent.h library, added currentTime, overrideTime, lastOvertide
  lastTXEvent, and lastCurrentEvent
* Added wrap-proof event timing and interval-based override timing.
* Add threshold calculation as 10x zero-state value, w/ minimum of 10