Block of updates on RSN package:

Block of updates on RSN package:

AliRsnDaughter:
- reorganized the list of methods
- added some utility getters which do a dynamic_cast into the allowed input types
- generalized the fRefMC data member to be able to get also the AOD MC particle type

AliRsnEvent:
- split the setter for main reference and MC reference
- added methods to dynamic_cast references to allowed input types for ESD and AOD
- splitted the SetDaughter(...) method for better readability, and implemented
  to cope with tracks and V0s both for ESD and AOD
- added a method to compute multiplicity using AliESDtrackCuts

AliRsnVAnalysisTaskSE-derived classes:
- adapted to splitted setters in AliRsnEvent

AliRsnValue:
- rewritten multiplicity-computation values

AliRsnCutPrimaryVertex:
- adjusted management of AOD primary vertex

AliRsnPair:
- manage AOD pairs

AliRsnAnalysisEffSE (**major update**)
- added all necessary code to run also on AOD MC productions