Merge pull request #2 from rmanzoni/fixit

bad chi2 tracks removed from sumpt2, new pixel vtx collection skimmer
new configs for the following purposes: 1_ use more than 1 PV for all the tracking iterations 2_ same as before but iter 3 and 4 are dropped 3_ second tracking configuration as proposed here https://twiki.cern.ch/twiki/bin/viewauth/CMS/HLTTrackingFor2015#New_HLT_Iterative_Tracking_Confi 4_ third tracking configuration as proposed here https://twiki.cern.ch/twiki/bin/viewauth/CMS/HLTTrackingFor2015#New_HLT_Iterative_Tracking_Confi
in progress