update matrix: fixed and DQMIO

. DQMROOT => DQMIO needs be extended to teh cmsDriver
. when using dqmio, set NEW! datatier name to DQMIO (in place of old DQMROOT)
. two new workflows GEN-SIM only, to prepare input of pileup workflows which don't have a no-pileup correspondent ; thanks to @fabozzi (ZmumuJets_Pt_20_300 and ZmumuJ
. gen2015 for ZmumuJets_Pt_20_300_13 => get correct GT (thanks to @fabozzi and @ferro)

. NOTE: access to sim geometry left purposefully xml-based for postLS1 samples, for consistency with the 70x cycle.