THcDriftChamber::SpacePoint -> THcSpacePoint
  That way space points can be put in a TClonesArray and be made known
  to THcDC when stub information is added.

  1)   Moved hardcoding of Yplane plane number to Addplane since it is called
     before ReadDatabase
  2) In FindEasySpacePoint add variable max_dist to match the code in
     h_find_easy_space_point.f more and fix problem
  3) As in h_find_easy_space_point  use max_dist instead
     of FSpacePointCriterion in IF statement to pick matching "x" hits.
In THCDC.h
  1) Set GetPicth and GetCentralWire as Double_t
  2) Set  GetSpacePointCriterion to return fSpace_Point_Criterion2[chamber-1]
     instead of sqrt

The arrays are  frPosTDCHits, frNegTDCHits,frPosADCHits and frNegADCHits
There are filled in THcScintillatorPlane:ProcessHits
2) Also modified THcScintillatorPlane::ProcessHits explicitly set variable
padnum=hit->fCounter and index=padnum-1 so the the TClone arrays for
scintillator variable set padnum=1,16 while the index=0-15
Want pdnum=1-16 because it is used in a hitogram fo counts versus
paddle number
3) Because of change to filling PaddleNumber in ProcessHits had
to modify THcScintillatorPlane::PulseHeightCorrection so the
index variable "j" is set to etPaddleNumber()-1 .

In the ENGINE, this can happen if a hit belongs to more than one space point.

  New class THcDC is whole set of wire chambers.
  THcDriftChamber is one chamber (6 planes)
  Implement space point finding from h_pattern_recognition up to point
     before where space point lists from the two chambers are combined.
  Includes
      FindEasySpacePoint   (h_find_easy_space_point)
      FindHardSpacePoints  (find_space_points)
      DestroyPoorSpacePoints (h_sp_destroy)
      SpacePointMultiwire  (h_sp_multiwire)
      ChooseSingleHit 	   (h_choose_single_hit)
      SelectSpacePoint	   (select_space_points)

Space points are arrays of structures in the THcDriftChamber class.  Will
probably need to take space points out class so that they can be looked at
at the THcDC level.

New code is only tested to see that it compiles and that space points
are sometimes found.

properly with 4. Before it was filled with 1,2,3,4 for each plane 1,2,3,4
2) Only if fTofUsingInvAdc==1 the read database for hodo_pos_invadc_offset, hodo_pos_invadc_linear
,hodo_pos_invadc_adc, hodo_neg_invadc_offset, hodo_neg_invadc_linear
,hodo_neg_invadc_adc

GN: finished debugging the hodoscope start time calculation. Results match 1-to-1 the corresponding "engine" result.

Started with Simon's code, but reworked:
	Use podd style arrays in RVarDef.
	Get plane names (1pr, 2ta, 3ta, 4ta) from parameter file.
	Get block counts from parameters instead of hardwiring.
	Rename histogram names to be A,B,C,D 1-13, instead of 1-52

of hardwiring them.

  It has not been check that we are getting a good start time yet.
  Drift time and distance added to tree
  Change DC plane names from 1, 2, 3, ... to 1x1, 1y1, ...
    This is so that the parameters holding the time to distance maps
       can be found.  (The parameters are e.g. hwc1x1fract)
    Need to find a way not to have to hard code these plane names.
       Either use wire angles (alpha) or some kind of parameter name mapping
  Changed output.def to match new plane names

Calculating pulse height correction for the hodoscope.
Calculating focal plane times for each scintillator plane - (in THcScintillatorPlane)
Calculating hodoscope start time (average of fp times) - (in THcHodoscope)

hodoscope start time.

Pass a start time computed in THcHodoscope to THcDriftChamberPlane. A dummy value for the start time is used until the Hodoscope code actually computes the start time.

    Define constants (e.g. plane counts) that are not defined in
    the ENGINE parameter files so that the detector classes
    can be more generic.
    Hodoscope and Aerogel now pick up plane and tube counts from this file

      Start adding to the drift chamber code.   Setup a class structure
      similar to what podd uses for the VDCs.  Raw hit class renamed
      to THcRawDCHit.  Signal hits are how THcDCHit, modeled after
      podd hits.  Add THcDCWire, and classes for time to distance conversion.
      Time to distnace conversion doesn't do anything yet.

      Find some improved DC parameter files so that min and max TDC limits
      are good for the run we are using.

      THcDriftChamberPlane asks ThcDriftChamber for many parameters.

xhodo.pos and xhodo.param
THcHodoscope generally holds:
- singular variables (i.e. central path through the spectrometer, min/max limits for the ADCs, TDCs, etc.)
- "padded arrays" (i.e. look at the plane with the most scintillators, allocate and array that has max_no_scint * no_of_planes - these are mostly found in the .param file)
THcScintillatorPlane generally holds:
- simple variables containing plane-specific info (z-position, scintillator size and spacing)
- arrays sized appropirately for the specific plane (i.e. individual x (or y) positions for all scintillators in a plane, signal propagation speed in the paddle, etc.)

    Register some more variables for the tree
    Clear fNelem of some arrays, not fNhits.
    Print method to print Aerogel pedestals.
    Make Pedestal analysis a bit more like the ENGINE.
    Initialize counters

Added haero.param to general.param.

Change shower plane names from 1z, 2z, 3z, 4z to 1pr, 2ta, 3ta, 4ta
  to match the names used in the parameters.
Fix up histogram names for new plane names.
Get rid of duplicate THaNonTrackingDetector::Init call.