Merge pull request #9 from jiafulow/prepare-v015

Commit unsaved changes before changing CMSSW release
Dropped RecoExtractor and SkimGeometry
Added scripts to study trigger towers
Added SingleElectron and SinglePi fragments
Added SingleMu fragments for one single trigger tower
Drop unused branches

- genJets, genMET
- TTTracks
- TTClusters: iLayer, iRing, iSide, iPhi, iZ
Updated NTupleTools unit tests
Updated AMSimulation unit tests