Custom drawing shouldn't require making a default plot first

[cdeil]

At the moment the tutorial shows that it is possible to draw the distributions and data yourself nicely be getting arrays like this:

((data_edges, datay), (errorp, errorm), (total_pdf_x, total_pdf_y), parts) = \ 
binned_likelihood.draw(fitter, parts=True);

Is it possible to change this so that it is possible to get these arrays without making a default plot first.
Maybe add an option to the draw method?

[piti118]

Yah I know... It was just a quick patch. We definitely need this function.