Lot's of changes to
 THcScintillator::ProcessHits
 THcHodoscope::EstimateFocalPlaneTimes
 THcHodoscope::FineProcess

  THcRawHodoHit gives reference time corrected TDC values
  THcScintillator plane adds a per plane offset to the raw tdc value
  First positive TDC value after adding offset is used

  in calculation of drift chamber start time

  Pulse height corrected times saved in THcHodoHit objects.
  PulseHeightCorrection method renamed to EstimateFocalPlaneTimes
    because the pulse height correction is now done in the
    ProcessHitsMethod.

   Don't repeat comparisons of tdc values
   with fScinTdcMin and fScinTdcMax because hits only get added to
   fHodoHits (and previously fPosTDCHits, fNegTDCHits, ...) if
   the times are within these ranges.
  In THcHodoscop, remove members of fTOFPInfo that are just used
   locally.