allow using the developing HLT menu for run2 in CMSSW_7_1_X

This pull request would allow using also in FastSim the HLT menu in development for run2 in CMSSW_7_1_0_pre9 without having to git cms-merge-topic on it.
It has no effect on the standard workflows, thus there is no way to test it (unless you ask me the recipe to run the HLT run2 menu...)
Re-submitting it for 71X