drop unused selectBaseEvent
get rid of unused SusySelectionMatt::setUseMCTrig
move the remaining functions from SusySelectionMatt to MeasureFakeRate2

Details:
move selectEvent, passWhSS, getEvtWeight, getBTagWeight to MeasureFakeRate2
Note that because increment() used getEvtWeight, getBTagWeight,
now the counters are broken; the histos are still fine though.
SusySelectionMatt: move increment implementation from h to cxx
move counter methods from SusySelectionMatt to MeasureFakeRate2; restore count printouts
SusySelectionMatt : get rid of unused TF1 m_BoundLow
move counters from SusySelectionMatt to MeasureFakeRate2
move WeightType enum from SusySelectionMatt to MeasureFakeRate2, add m_ET
MeasureFakeRate2: forgot to initialize m_ET
MeasureFakeRate2: inherit from SusySelection rather than SusySelectionMatt
drop remaining (unneeded) include SusySelectionMatt
delete SusySelectionMatt