miniAOD part4 (7.2.X, only PatAlgos and cmsDriver)

Propagate a few committs that we had only in the 70X part3 pull request #4008 and not in the merged 72X PR (#3946) and avoid another ak4-ak5 issue in mc flavour for met uncertainties (which does not apply to 70X)

Will backport to 71X when  #3875 wil be merged (it's the same branch as the already merged #3946, and weeks old, so I hope it will go in soon)

Tested with

    # after runTheMatrix.py -l 4.75,25202.0,25401.0
    cmsDriver.py miniAOD_data-prod -s PAT -n 100 --data      --filein file:$PWD/4.75_RunJet2012D+RunJet2012D+HLTD+RECODreHLT+HARVESTDreHLT/step3.root     --eventcontent MINIAOD    --runUnscheduled --conditions auto:com10_GRun --scenario pp --no_exec
    cmsDriver.py miniAOD-prod      -s PAT -n 100 --mc        --filein file:$PWD/25202.0_TTbar_13+TTbar_13+DIGIUP15_PU25+RECOUP15_PU25+HARVEST/step3.root  --eventcontent MINIAODSIM --runUnscheduled --conditions auto:run2_mc    --magField 38T_PostLS1 --customise SLHCUpgradeSimulations/Configuration/postLS1Customs.customisePostLS1 --no_exec
    cmsDriver.py miniAOD-fsim-prod -s PAT -n 100 --mc --fast --filein file:$PWD/25401.0_TTbar_13_AVE20+TTbarFSPU13AVE20+HARVESTFS/step1.root              --eventcontent MINIAODSIM --runUnscheduled --conditions auto:run2_mc    --magField 38T_PostLS1 --customise SLHCUpgradeSimulations/Configuration/postLS1Customs.customisePostLS1 --no_exec

@arizzi