[WIP] Updating cross-sections of processes for both 7 TeV and 8 TeV; updati… n...

...g bash and python scripts for 7 TeV running for samples recently made available.
This is DICE-specific, I wouldn't put it here (or make it conditional)
as well as sourcing thisroot.sh on DICE

This recipe is not just for DICE — cmake is useful for compiling on macs, where CMSSW is unavailable.