Store jet ID used for T1 MET corrections

[andrey-popov]

Store results of jet ID used in centrally provided T1 MET corrections to reject leptons reconstructed as jets. This should allow recomputing corrected MET exactly starting from PEC files.

[andrey-popov]

Unlike the cut on the EM energy fraction, the part related to muons is more difficult: four-momenta of muons are actually subtracted from jets. This is enabled in the standard configuration:

>>> process.patPFMetT1T2Corr
cms.EDProducer("PATPFJetMETcorrInputProducer",
    jetCorrLabel = cms.InputTag("L3Absolute"),
    jetCorrLabelRes = cms.InputTag("L2L3Residual"),
    offsetCorrLabel = cms.InputTag("L1FastJet"),
    skipEM = cms.bool(True),
    skipEMfractionThreshold = cms.double(0.9),
    skipMuonSelection = cms.string('isGlobalMuon | isStandAloneMuon'),
    skipMuons = cms.bool(True),
    src = cms.InputTag("cleanedPatJets"),
    type1JetPtThreshold = cms.double(15.0)
)

This cannot be implemented with an ID flag. On the other hand, this shouldn't probably be done in the first place given that muons with p_T down to 10 GeV are considered in the analysis explicitly, and jets are cleaned against them.