New version (v2) of the xAOD::TrackCaloCluster EDM objects
We modify the xAOD::TrackCaloCluster class so it can also accomodate links to other objects than CaloClusters. In practice, after discussions with EDM experts, only a new version of TrackCaloClusterAuxContainer is needed, so a new TrackCaloClusterAuxContainer_v2 is introduced and corresponding changes to TrackCaloCluster_v1 are done.