R22 migration of egamma derivations.

Migrate egamma derivations to R22. First working version, tested on R22 samples.

ELReset error messages for AntiKtEMTopo jets might appear when running over buggy xAODs, can be fixed with preExec option from AthenaCommon.DetFlags import DetFlags;DetFlags.detdescr.all_setOff(); DetFlags.BField_setOn(); DetFlags.detdescr.Calo_setOn(); DetFlags.pileup.all_setOff(); DetFlags.overlay.all_setOff();