Put a minimum cut on reference times.

   First hit above this cut is taken as the reference time.
   Cuts are per detector and read as an optional parameter in
   each detector class.  TDCs and Flash ADC times have separate cuts.

Implement a second method of selecting best reference time.
  If InitHitList is passed a possitive reference time cut,
    use the first reference time above that cut.  If none of the
    hits pass the cut, then no reference time is set
  If InitHitList is passed a negative cut, the cut is taken to be
    the absolute value of the cut, but a reference time is garuanteed
    to be set as long as there is at least one reference time hit.
    If none of the reference time hits pass the cut, then the last
    hit is taken to be the reference time.  (Should be the largest.)

Allow reference time cuts for all the spectrometer detector classes
  Hodoscopes, drift chambers, Aerogels, Gas Cherenkovs, Calorimeters