THcShowerHit.h and THcShowerHit.cxx
---------------
1) Added fY for horizontal position
2) Added fY to THcShowerHit

THcShower.h
-----------
1) Added variables
2) Added method addY, clY to get the cluster Y position

THcShower.cxx
--------------
1) Added variables to the tree for "layer" detector
    either SHMS preshower or HMS layers
2) Added variables if the SHMS "array" is used
3) Added y position to THcShowerHit in CoarseProcess
4) In FineProcess, if SHMS "array" used then fill X,Y info
     for the Cluster and the "best" track that matched the cluster

THcShowerArray.h and THcShowerArray.cxx
---------------------------------------
1) Added methods to Get the array cluster size, X and Y position
   and block number that has the highest energy in the cluster
2) Added array fBlockClusterID for all blocks. initialized to -1
   for each block for each event and then filled with
   the cluster number if the block is included in the cluster
3) Add variable fNhits and fNgoodhits

       This is to match the class name defined in those files
       Also add THcShowerHit to the Makefile

THcShowerHitClass.h file.