#4734 histogram_description clobbers xrange

[Robert Dodier]

Documentation says xrange can occur anywhere in a scene, but histogram_description clobbers whatever value of xrange is already in the scene with the range of the histogram. xrange has to be placed after histogram_description in order to the range of the displayed figure to be equal to xrange.

Example: This first figure has the incorrect x range; it is the range of the histogram instead of xrange.

load (descriptive);
draw2d (xrange = [0, 20], histogram_description ([5, 6, 6, 7, 7, 8, 9, 9]));

Second figure has correct range because xrange is placed after histogram_description.

draw2d (histogram_description ([5, 6, 6, 7, 7, 8, 9, 9]), xrange = [0, 20]);

I guess we should look to see if other scene elements have the same defect. I didn't check.