cms-sw/cmssw — pull request #6692 by franzoni (2014-11-28 19:18:27+00:00)
Title: assure no DS collision LHE relvals

- needs to go on top of #6626 (already rebased on top of CMSSW_7_4_X)
- enforces that no LHE workflow can produce the same /GEN dataset
- /GEN recycling command all point to the same /GEN dataset