add tracking validation sequence
comment it out the hltPFlowTrackSelectionHighPurity collection (it is not available yet :( )
modify the tracks collection to be monitored .. for the mean time
migrate to getByToken
migrate to getByToken
add ignore missing track collection in both hltMultiTrackValidator and hltTrackingParticleRecoTrackAsssociation (it was the source of crashes)
update SimpleMagneticField also RungeKuttaTrackerPropagator
Merge pull request #3703 from mtosi/from-CMSSW_7_1_0_pre7_HLTtrackingValidation

tracking HLT validaiton