message: only add output handler when not yet there
diff: @@ -26,6 +26,7 @@ AliAodSkimTask *AddTaskAodSkim(const Double_t mine=5,
  cout << "-> name=0" << endl;
  cout << "Writing skimmed aod tree to " << fname.Data() << endl;
  + if (mgr->GetOutputEventHandler()==0) {
  AliAODHandler *output = new AliAODHandler;
  output->SetOutputFileName(fname);
  output->SetFillAOD(1);
  @@ -33,21 +34,21 @@ AliAodSkimTask *AddTaskAodSkim(const Double_t mine=5,
  output->SetFillExtension(0);
  output->SetTreeBuffSize(30*1024*1024);
  mgr->SetOutputEventHandler(output);
  + }
  AliAodSkimTask *task = new AliAodSkimTask(tname);
  task->SetClusMinE(mine);
  task->SelectCollisionCandidates(trigsel);
  cout << "Task configured with: " << task->Str() << endl;
  -
  -
  mgr->AddTask(task);
  +
  AliAnalysisDataContainer *cinput = mgr->GetCommonInputContainer() ;
  TString contName(tname);
  contName += "_histos";
  AliAnalysisDataContainer *coutput = mgr->CreateContainer(contName.Data(),
  TList::Class(),
  AliAnalysisManager::kOutputContainer,
  - Form("%s", AliAnalysisManager::GetCommonFileName()));
  + Form("%s_histos.root", tname.Data()));
  mgr->ConnectInput (task, 0, cinput );
  mgr->ConnectOutput (task, 1, coutput );
  