[PATCH] Correct handling of corner radii of rectangles

[Christina Roßmanith]

Hi,

in createPolygonFromRect the interval [0,1] is scaled to 
[width/2,height/2]. Hence rx and ry have to be divided by width/2 and 
height/2 respectively - I totally agree with Marco (cf. Re: 
svgreader.cxx: XML_RECT question).

The attached rounded_rect.svg tests the case that rx=width/2 and 
ry=height/2 which should be rendered as an ellipse.

Christina