changes to synchronise selection for muon channel and weights
add reference to btag weight twiki
Merge pull request #52 from phy6phs/synchronise

Synchronise with ATs
Synchronisation of electron selection in NTupleTools with AnalysisTools. This is a work in progress so do not merge yet. I am making the pull request so that people can see what I have changed so far and comment on whatever is
still to be corrected:
- Changed EcalDeadCellBoundaryEnergyFilter to EcalDeadCellTriggerPrimitiveFilter in python/TopPairElectronPlusJets2012SelectionFilter_cfi.py (removed discrepancy in trigger & event cleaning step). I see from Sergey's comments
in Phil's pull request that some more filters and stuff need to be added here...to do.
- Changed passesd0 requirement to fabs(...) in isGoodElectron in plugins/TopPairElectronPlusJetsSelectionFilter.cc.
- Added hadronicoverEM in isGoodElectron in plugins/TopPairElectronPlusJetsSelectionFilter.cc.
- Added two separate variables in python/TopPairElectronPlusJets2012SelectionFilter_cfi.py called useDeltaBetaCorrectionsForMuons (true) and useDeltaBetaCorrectionsForElectrons (false) to use in the appropriate electron and muon
functions in plugins/TopPairElectronPlusJets2012SelectionFilter.cc.
- Removed isGlobalMuon from isLooseMuon in plugins/TopPairElectronPlusJetsSelectionFilter.cc.
- Changed passesConversionVeto  in plugins/TopPairElectronPlusJets2012SelectionFilter.cc to require that there is exactly one isolated electron, just like in the AnalysisTools.