Signal model and combineHarverster improvements/fixes

Signal model fixes:
- transfer matrix naming for correlated nuisances
- vertex deltafrac name
- diagnostics/debug scripts

combineHarvester:
- automatic nuisance freeze / float
- added profileMH option
- added RBinScan and RDiffXsScan for differential cross-sections
- fix parallel jobs working dir for --runLocal --parallel
- autodetect globe root