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.

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

work for any derived class.

THcHodoscope, a multiplane scintillator array.  Make a Hall
C style spectrometer (so that default Hall A detectors are not
included.)  Can read a Hall C data file and print out hodoscope hits
where the left/right TDC/ADC are matched up per counter.

constructors so that they now work in TClonesArray.