Progress with factorization of the reconstruction in the ITS (AliITStrackerMI):

 Progress with factorization of the reconstruction in the ITS (AliITStrackerMI):
many hard-coded numbers moved from AliITStrackerMI to variables in AliITSRecoParam;
included options to switch-off V0 finding in the ITS, cluster sharing, assignment of
virtual clusters in the dead zones and gaps;
the position of the gaps (in z) in the SPD layers is taken from TGeo; all the material
budget can be taken from TGeo (thanks to Ludovic), but not yet by default (too slow,
working on shortcuts).
Modified classes:
-AliITStrackV2: method PropagateToTGeo() to get material from TGeo
via AliTracker::MeanMaterialBudget (thanks Andrei, Marian, Yura).
-AliITSRecoParam
-AliITStrackerMI
The material budget can be taken from TGeo by explicitly enabling an option in the rec.C macro:
 AliITSRecoParam * itsRecoParam = AliITSRecoParam::GetLowFluxParam();
 itsRecoParam->SetUseTGeoInTracker(kTRUE);
 //itsRecoParam->SetFindV0s(kFALSE);
 //itsRecoParam->SetAllowSharedClusters(kFALSE);
 //itsRecoParam->SetAddVirtualClustersInDeadZone(kFALSE);
 AliITSReconstructor::SetRecoParam(itsRecoParam);

Andrea