prepareEventVariablesFriendTree: add option -D to select datasets using a regexp, and option -m to select which modules to run (to avoid having to comment and uncomment them)
validate basic multilepton quantities (for testing pull requests)
Bring in developments done before #129
now the validation script can actually spot differences
Merge pull request #130 from gpetruc/CMG_MiniAOD_Lite_V6_0_from-CMSSW_7_0_6

improvements to friend tree production, and validation scripts