THcDriftChamber
    New flag fHMSStyleChambers to determine if HMS or SOS style
    tracking should be done.  Flag is set on if the spectrometer
    name begins with 'h'.
    THcDriftChamber::LeftRight fSmallAngleApprox must be set and
    fHMSStyleChambers must be off to do SOS style.
    If not HMS style, ignore all the Yplane optimizations
  THcDC
    SOS code does "project to chamber" in link stubs.  Need to evaluate
    if this is necessary, or if HMS style should also do it.

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.

1) Need to add fNelem to DBRequest to read parameter arrays.
2) Added optional variable and set to true. Flag in the
DBRequest to tell code that parameter is optional
and does not have to be found.
3) Move setting of fNelem to before DBRequest for aero_num_pairs
 so that it can be overwritten by parameter file.

purposes.

- Add MacOSX-dependent compile options in Hall C LinkDef

  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.

Add fTheta_lab
Do offsets in THcHallCSpectrometer::ReadDatabase

  If ThcAnalyzer::PrintReport sees a format descriptor with 'd' at
  the end, then the value is converted to the nearest int before formatting.

    Added variables using ENGINE names
       gen_run_number
       gen_run_starting_event
       gen_event_id_number

   This is magic that allows the size of arrays to passed to
   the root tree making.

Inspired by ENGINE/CTP report generator
  Reports generated by
    THcAnalyzer::PrintReport(templatefilename,outputfilename)
    template is copied to output, {stuff} is replaced by the
       value of stuff.  Value can be formated with c formater, eg.
           {stuff:%.2f}
  ThcFormula added to allow more flexibility of variables.
    Can get number of times cuts pass or are called with:
       cutname.npassed (or cutname.scaler) and cutname.ncalled

Re-arrange, modify and make more detailed comments in the Shower*.h header
files. Add more comments in the Shower*.cxx files.

Changed column and row numbering in THcShowerHit.h in order to get rid of
warning messages on unsigned and integer comaprisons when compiling;

Corrected a debug message in THcShower.cxx.

  Use HALLC_MODS in make file to turn on Hall C changes in Podd.
  Remove unneeded and now broken includes of THaDB.h.

   {prefix}dc_fix_lr
        Historically, in the ENGINE, if a hit is used in multiple
        space points/stubs, the left/right assignment for that hit, which
        is later used in track fitting, is that assigned for the last stub
        encountered with that hit.  Properly, the left right assignment
        should be allowed to be different in different space points.  If
        this parameter is set to zero (e.g. in hcana.param), then the
        ENGINE behavior is used.  For new analyses, it should be set to one.
        (Which is the default)
   {prefix}dc_fix_propcorr
        When a hit gets put into a stub, the distance of the hit from the
        discriminator can then be estimated.  In the engine, a correction to
        the drift time (and thus drift distance) is applied.  However, if
        that hit ends up in another stub, the correction will get applied again,
        resulting in a over correction.  Setting this flag to 1 will give that
        hit a different corection for each stub that it is in.

These flags will default to the new "correct" way of handling hits if
the above parameters are not set in a parameter file.  Currently, both
flags are set to zero in hcana.param to replicate the ENGINE behavior.

To implement these changes, the propagation correction and L/R information
for each hit is saved in space point and track classes.  This information
is still saved in the hit class, but only used if in ENGINE compatibility
mode.

The THcDCTrack class now saves a list of space point pointers instead
of space point indices.

The AddSpacePoint method now also copies all the hit information into
the track object so that THcDC doesn't need to explicitely copy all
the hits.

The FindStub method, which fits a stub track to a space point is passed
the space point rather than a list of hits

1.  nplusminus was not initialized corectly so small angle approximation
was never used.
2.  Change MAXTRACKS from 50 to 10 to match ENGINE.

  Name of coefficient file in hcana.param
  Some basic hms setting parameters added to test.database for run 50017
  Traceback code in THcHalCSpectrometer

is set hdbg_clusters_cal in hdebug.param