[changeset] - have the gnuplot backend respect properties

[Ben Abbott]

I've put together an initial changeset for the gnuplot backend which  
respects several properties of the root and figure.

The properties included are root.screensize, root.screenpixelsperinch,  
figure.papersize, figure.papertype, figure.paperposition, figure.name,  
figure.numbertitle, figure.position, & figure.units.

Regarding position information, the coordinates are ignored, but the  
figure/canvas size is respected by the gp terminals which support a  
size option. At the present, that excludes x11, but that there appears  
to be an discussion/effort to correct that. See the link below.

https://sourceforge.net/tracker/index.php?func=detail&aid=1553072&group_id=2055&atid=302055

The gp canvas size is that area respecting the plot itself, which  
corresponds to an area of figure.position(3:4).

This changeset assumes the prior changeset to add screensize &  
screenpixelsperinch to root is applied.

gnuplot_drawnow.patch
Description: Binary data