fixing bug where brem var was NaN which causes out of bound array accesses.
modify generic gridpack run script to allow using different compression types (in particular xz, which is needed to keep larger gridpacks under the 1GB frontier limit)
fixed M1 cfg file
Merge pull request #6043 from bendavid/gentunelhefix_72x

Fix for UE tune fragment and improvement to LHE run script (72x)
Merge pull request #5959 from Sam-Harper/EGM72XEUncertaintyFix

fixing bug where brem var was NaN which causes out of bound array access
Merge remote branch 'origin/CMSSW_7_2_X' into CMSSW_7_0_X