explicit DQMIO in datatier of GEN relvals
Merge pull request #5730 from franzoni/GEN-relval-CMSSW_7_3_X_2014-10-07-1400

 Gen relval cmssw 7_3_X_2014-10-07-1400
Merge remote branch 'origin/CMSSW_7_3_X' into CMSSW_7_0_X