Align to new ROOT 5.34.18 API

`TVector3(double x=0,double x=0,double x=0)` got changed to
`TVector3(double x,double x,double x)` so this rehestablish behavior.
Merge pull request #3915 from ktf/fix-dqm-datascouting

DQM -- Align to new ROOT 5.34.18 API
Merge remote branch 'origin/CMSSW_7_1_X' into CMSSW_7_0_X