New version of the GS msc model plus cleanup.

New version of the GS msc model that is in perfect sync with the one that will be available in Geant4.10.4 (next week). The updated GeantV EM simulations give below per mille agreement with the corresponding Geant4 simulations (using Geant4.10.4 candidate00).

Both the general simplified sampling calorimeter (TestEm3) and the full-cms applications (both Geant4 and GeantV) are available now and provide the same physics simulation results. Therefore, they are ready for profiling.