modified:   config.env

merged in changes from upstream, including major changes to the THcHodoscope class. I had to manually propagate some of these changes because of the differences in implementation for this classs.

1) THcDC
a) Add variable to tree called dc.InsideDipoleExit
which is a Bool_t flag that is kTRUE if golden track is inside the
dipole exit. Uses THcHallCSpectrometer::InsideDipoleExitWindow
in THcDC::SetFocalPlaneBestTrack to set variable.

2) THcHallCSpectrometer
a) Add method Bool_t InsideDipoleExitWindow which checks whether
the track is within the dipole exit window. Checks
prefix used for database to set flag
fUseSHMSDipoleExitWindow or fUseHMSDipoleExitWindow
to be true which is used in InsideDipoleExitWindow
to select either SHMSDipoleExitWindow or
HMSDipoleExitWindow method to be used as the test.
b) Hardcoded z distance from spectrometer focal plane to
dipole exit window.
c) Methods Bool_t SHMSDipoleExitWindow and
Bool_t HMSDipoleExitWindow return true/false if
the track was inside/outside the dipole exit window.
d) Added dipole exit window test to the BestTrackUsingPrune
method. Need to set parameter hprune_DipoleExit=1 or
pprune_DipoleExit=1 to use the test in the method.
By default it is turned off.

The LeftRight method determines the sign of the wire
distance for each hit in the spacepoint by looping
through all combinations of wire signs and fitting each
combination with a line  and selecting
the combination with the lowest chi-squared.
The fit to the line is known as the "stub" which
is an array of the x,dx/dz, y and dy/dz of the fit
and is associated each spacepoint. The stubs are
used later in LinkStubs method
to match spacepoints between two chambers to give a
possible tracks.

Previously the LeftRight method would only fit a
stub for a spacepoint with 4 hits in the chamber if the
parameter flag  HMSStyleChamber was true.
HMSStyleChamber refers to the 6 GeV HMS chambers
and we do not have them anymore.
But not fitting the spacepoint, the stub
was filled with zeros for x,dx/dz,y and dy/dz
and these spacepoints would never be matched with
other spacepoints to form a possible track.

In method TrackCalc get the proper THcDCTrack array index
from the golden track by using method GetTrkNum
for use in the THcDC method
SetFocalPlaneBestTrack.

When creating the THaTrack array in THcDC::CoarseTrack
the array index between THaTrack and THcDCTrack arrays
 match. The THaTrack is also associated with the THcDCTrack
array index with the call SetTrkNum(index+1)

When selecting best track by lowest chi-squared the
THaTrack are sorted from lowest to highest chi-squared
The code made a mistake in the index used in
 SetFocalPlaneBestTrack. It used the array index of the
THaTrack which is now not in sync with the THcDCTrack.
Fixed problem by using the THaTrack method GetTrkNum
which gets the proper THcDCTrack array index.


This did NOT effect reconstructed target variables or
physics variables. It only effected the focal plane
varaiables that were selected as the "best" or "golden"
to be used for the tree for dc.x_fp , dc.xp_fp,
dc.y_fp , dc.yp_fp and for the residuals.

THcScintPlaneCluster is a new class to hold information
about scintillator plane clusters of paddle hits.
The clusters of paddles for each plane are formed in
THcHodoscope::TrackEffTest which is used in the tracking
efficiency.

Modify THcScintillatorPlane so that the cluster information
(number of clusters, size,pos, flag if cluster used)
is in the tree.

Modify THcHodoscope::TrackEffTest so position
difference  are taken for all clusters in X1 (or Y1)
with all clusters in X2 (Y2).

In THcDC.h change MAXTRACKS from 10 to 50. The maximum
number of tracks is set by parameter ntracks_max_fp

Previously the LinkStubs method would not create
a track if the total number of spacepoints in
the two chambers was larger than 10.

Now LinkStubs will create a vector of THcSpacePoints
of up to 100 spacepoints with no more than
50 spacepoints from chamber 1 and use that
to find possible tracks.

I