Fitting

The scripts in experimental were used for debugging the fit.

Changes in the actual fitting used in the analysis:

- LL divided by number of templates
- gMinuit.SetErrorDef( 0.5 ) for LL errors (was 1)
- Remove constraints on QCD and V+Jets
- Set initial QCD template normalisation to 0.1 if less than 0.1


please do not remove the constraints here.
They are not used if you don't specify them in the FitCollection. No reason to remove the code for the moment