first batch of SM updates for e-tau and mu-tau

 - Update ZL stat. uncertainty nuisances in low stats 8TeV categories
   7TeV update pending
 - 8TeV W nuisances now combine latest stat uncertainty, ersatz
   recommendations, and new uncertainty for extrapolation factors
   from relaxed category selections
 - Updated 7 & 8TeV diboson stat uncertainties
fix a few bugs in the last commit and remove comments
Merge pull request #153 from ajgilbert/cfg-updates

config file updates