- Common input and output data containers are now created automatically when attachin...

- Common input and output data containers are now created automatically when attaching an input or output event handler to the analysis manager. One has to connect his task to these containers via:
   mgr->ConnectInput(myTask, 0, mgr->GetCommonInputContainer());
   mgr->ConnectOutput(myTask, iout, mgr->GetCommonOutputContainer());
 (M. Gheata)
- Protection added in AliAnalysisTaskSE for user tasks that are not connected to an output AOD container.
- Protection added in AliAnalysisManager::ConnectInput/Output() when the task pointer is NULL