- Added a cut class for selecting the trigger mask (waiting for filters)

- Added a cut class for selecting the trigger mask (waiting for filters)
  --> this caused modification in libPWG2resonances.pk and PWG2resonancesLinkDef.h

- Fixed initialization of data members in AliRsnPairDef

- Added a mass data-member to AliRsnCutStd to allow cutting on rapidity
  --> only valid assuming a resonance mass hypothesis

- AliRsnFunction: modified strongly the output objects:
  a) if one adds up to 3 axes to the output, it will be a TH1D, TH2D or TH3D
  b) if one adds >3 axes, it will be a THnSparseD (with a warning about the size)
  --> in any case, the user can force to use THnSparseD by calling AliRsnFunction::SetSparse()
  --> this caused some modifications also in AliRsnPair and AliRsnAnalysisSE classes