add egamma PFIso to derivation
EGamma pflow isolation is not computed at reco. This MR allows to have it at derivation level. For the time being, it is only switched on in EGAM1 and EGAM10 for studies. It computes pflow neutral iso for std pflow objects and also CSSK objects.
This MR also implements the supercluster core subtraction for pflow isolation, for studies.
It also fixes a few warning messages due to non existing variables expected to be written in DAOD, and switched off the computation of "LooseCone" track isolation for muons.
ping @lpascual : if you think it is useless, we can just close the MR
ping @gmarchio as derivation expert : what are the tests to perform to check this does not mess up derivation jobs ? (Of course producing locally EGAM1 with master is working smoothly)