Increase scale maximum values
Created by: Famlam
I tried to overlap two spectra (using the plot->Multiplot function) which differed in intensity by a factor 2500. Surprisingly ssNake didn't allow me to do so. (I could do it the other way around, fortunately, using a scale value of 0.0004). This PR increases the limits on the 'scale' entry boxes to ±1e6