Make association of hit clusters to tracks in the HMS more
consistent with Engine.

	   Reverse order of cycling through clusters in THcShower::MatchCluster.
Add a script for event-by-event comparison of energies of the best
track in Engine and the golden track in hcana.

      Add directory examples/gtrk_e holding the code.
Remove analysis of the maximum cluster and cluster association to the
first track from the HMS shower counter code.

    Remove variables and code related to the maximum cluster of hits,
    and association of a cluster to the 1-st spectrometer track in
    THcShower.h and THcShower.cxx. Those were used for testing of the
    code, not needed any more.
Add float precision calculation of the X coordinate of hit clusters in
the HMS calorimeter.

    Add src/THcShowerCluster.h.float, a version of THcShowerCluster
    class with float precision calculation in clX method.