dataaspectratio & plotboxaspectratio

[Ben Abbott]

Currently the gnuplot backend ignores (I think) the plotboxaspectratio, and 
treats the dataaspectratio as Matlab treats plotboxaspectratio.

For 2D plots, with axes units=centimeter / inches / pixels / points the correct 
interpretation would be ...

        plotboxaspectratio = the aspect ratio of the rendered plot box.

        dataaspectratio = [diff(xlim), diff(ylim), diff(xlim)] / min 
([diff(xlim), diff(ylim), diff(xlim)])

Related to these axes properties are two functions that are not yet included in 
Octave, pbaspect(), and daspect(). I hope to add these today or tomorrow.

I'd also like to correct how Octave treats the dataaspectratio and 
plotboxaspectratio.

My thought was to go through m-files in scripts/plot and manually do a search 
on dataaspectratio and replace it with plotboxaspectratio (I'll handle the 
"mode" properties as well).

As I expect changing this behavior will result in quite a few emails, I thought 
it prudent to give a heads-ups and ask if there are any concerns, advice, 
and/or objections?

I'm not familiar with how the FLTK backend treats these properties, but expect 
it is preferred to correct this problem now as opposed to later.

Ben