several changes to fix the access to ele aux info

- change initialization order: now doing the same as
  SUSYToolsTester (event, store, susyObjDef)
- XaodAnalysis::xaodElectrons: retrieve also the aux info
- make xAOD::TStore a datamember
- make ElectronContainer* and its ShallowAuxContainer*
  datamembers (circumvent the constness of 'retrieve'
muon aux
tau aux (and drop const)
jet aux
photon aux
initialize internal aux; deleteShallowCopies
perform overlap removal