Base class THcRawHit has null GetReference method.  Returns
  zero.
  THcRawDCHit will get the reference time if it was specified in the map file.
  It is up to the detector class to use the reference time to subtract off
  pipeline TDC jitter.

  Modify THcFormula and THcParmList to match changes to THaFormula
     (needed for reports)
  Small changes in THcInterface and detector classes for compatibility
     with new OO decoder and podd 1.6

  For the most part this is making sure that the loop variable in
  a for loop is of the same type as the variable that it is compared
  against (Often a UInt_t).

This reverts commit e9ce1040.

Conflicts:
	src/THcHallCSpectrometer.cxx

  For the most part this is making sure that the loop variable in
  a for loop is of the same type as the variable that it is compared
  against (Often a UInt_t).

In tree they are called tnhit and trawhit.
Created two new variables for THcDriftChamber, fNthits and fN_True_RawHits.
In tree they are called tnhit and trawhit.
THcDC defined subdetector THcDriftChamber to have name Ch1 and Ch2 to do used in the tree.
THcDriftChamberPlane defined new method GetNRawhits to return fNRawhits for each plane.
Added member fNRawhits to THcDriftChamberPlane

These were related to a) scope of some variable declarations, and b) use
of pre-increment vs. post-increment of non-primitive types (this has a
slight performance hit due to the way that pre- vs. post-increment
operators are overloaded in C++.

Also cleaned up a few places where initialized variables were not being
used.

  Clone some DC tests from ENGINE test files to podd
  style cuts.  Make changes to source code to support these tests.
  Correct hits in plane line in example report file.

  Uses ROOT matrix math instead of solve_four_by_four
  Nothing is done with found tracks yet.  Will need to stuff these into
     podd style tracks.  (Or a class inherited from podd style tracks.)
  Residuals not saved anywhere
  Single stub mode not yet implemented
  No printing out of trackfit results (hdebugtrackprint)

  Compiles and doesn't crash.

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

  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.

  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

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.

      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.

for older ROOT version wasn't working.

be made either in output.def or by analyzing root tree.