Moved G4 EM parameter definition from SetCuts() to ConstructProcess()

1) This move is needed for MT mode, no effect on sequential.
2) Added option to enable GFlash for hadronic showers - needed for validation of FastSim. 
3) Fixed compilation problems seen when compile versus  recent Geant4 release 10.1.
4) Removed obsolete headers.

 All this modifications do not affect production runs