improve airfoil display

[robe191]

To better visualize the differences of airfoil coordinates and bezier spline representation, the following could be done:

-blow up the z coordinate a factor defined by the user (5 could be typical)
-indicate the position and maximum difference of initial airfoil to bezier airfoil

[jxjo]

yes ...
I already had implemented such a "show difference" - I think with a factor of 10.
But then removed it again, because it looked quite confusing with all the "lines" on the screen...

May be a separate y-scale would be more helpful (currently x,y-scale are the same).
What you think?