Normalised plots

Created by: voisey

Some plotting files have been edited so that plots such as the ones here http://pcteserver.mi.infn.it/~nnpdf/validphys-reports/WHp0mMmZRHWdgnxMxWl1dw==/ are plotted separately for different values of x or Q, to avoid points being plotted on top of one another. The new plots can be seen here http://pcteserver.mi.infn.it/~nnpdf/validphys-reports/t7pE1PqNRG6kT3K1A685cQ==/