Add doxygen groups "Apparatuses" and "Decoders"
  Make sure every class is in a group
  Make sure most classes have a \brief description
  Improve comments for some classes including THcHallCSpectrometer
     and hodoscope classes
  Change some Doxyfile defaults.  Include sources files.

  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

      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.

TClonesArray ConstructedAt method.

Raw hit class for drift chambers and skeleton drift chamber that prints
out drift chamber package hits.

Move Compare method from THcHodoscopeHit to ThcRawHit since it should
work for any derived class.

Get detector name -> ID mapping from the map file comments