message: Fixes needed for ROOT6
  Forward declaration of function CreatePythia8Gen missing,
  therefore function was not found
  For yet unclear reason AliPythia8::Instance() and
  new AliGenPythiaPlus ... must be executed in different
  lines, otherwise it ends in "illegal instruction"
diff: +AliGenerator* CreatePythia8Gen( Float_t e_cms,
  + Int_t tune,
  + Bool_t kCR,
  + Int_t kF,
  + Int_t kProcess,
  + Double_t ptHardMin,
  + Double_t ptHardMax
  + );
  +
  AliGenerator* Add_MCGenPythia8_TuneX( Float_t e_cms = 2760.,
  Int_t tune = 5,
  Bool_t kCR = kTRUE,
  @@ -39,7 +48,8 @@ AliGenerator* CreatePythia8Gen( Float_t e_cms,
  gSystem->Setenv("LHAPATH", gSystem->ExpandPathName("$ALICE_ROOT/LHAPDF/PDFsets"));
  - AliGenPythiaPlus* gener = new AliGenPythiaPlus(AliPythia8::Instance());
  + AliPythia8 *pythia = AliPythia8::Instance(); // For ROOT6 needs to be created before AliGenPythiaPlus object, otherwise ending in "illegal instruction"
  + AliGenPythiaPlus* gener = new AliGenPythiaPlus(pythia);
  std::cout << "*****************************************************************" << std::endl;
  std::cout << "Process: "<< kProcess << "\t Color reconnection: "<< kCR << "\t Tune: " << tune << "\t kFactor: "<< kF << std::endl;
  @@ -55,7 +65,7 @@ AliGenerator* CreatePythia8Gen( Float_t e_cms,
  if(kProcess==1) {
  gener->SetProcess(kPyJets);
  - std::cout << "went into jet loop" << endl;
  + std::cout << "went into jet loop" << std::endl;
  if(ptHardMin > 0.){
  std::cout << "Setting pTHardMin: "<< ptHardMin << "\t ptHardMax: "<< ptHardMax << std::endl;
  gener->SetPtHard(ptHardMin,ptHardMax);
  