update_premixInput + update datatier as per https://hypernews.cern.ch/HyperNews/CMS/get/comp-ops/1658/1/1/2/2/1/2/2/1.html
eventcontent=>PREMIXRAW ; datatier=>PREMIX-RAW
Merge pull request #4351 from franzoni/GF_update_premixInput_from-CMSSW_7_0_6

Gf update premix input from cmssw 7 0 6