Simplify EnergyPulser progress tracking

EnergyPulser progress is currently being tracked in multiple stages (which are basically unused) and in a manner mimicking engine heat.  This patch reduces progress tracking down to just a tick count and corrects what appears to be a bug in the timing.  (Reading the code suggests that pulses are intended to occur on the fifth tick after activation and every ten ticks thereafter, but currently occur on the seventh and every eleven thereafter.)