Rework and rename FLAG_IGNORE_MC_STATERR to now exclude the MC sample
statistical error as well as the theory prediction error. Only to be
used for DiffXSec, removed from Yield mode extraction. Updated docu
accordingly.
Mute diffxs file loading function a bit. no need to double print info...
Simple function for stat error on systematics calc (turned out to
be just a subtraction, but hey...)
extend stat. error scan range to 5 GeV
write out normal stat error if we have FLAG_IGNORE_MC_STATERR
Rework syst stat error calculation for DiffXSec. Should be fine now
except for minor tweaks in the LaTeX printout.