[Patch] Make fill-opacity and stroke-opacity available to renderers

As the title says, this makes the parser store the fill-opacity and stroke-opacity values. This works on this SVG with my Allegro 5 renderer:

<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN"
"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg xmlns="http://www.w3.org/2000/svg">
<style type="text/css">
circle:hover {fill-opacity:0.9;}
</style>
<g style="fill-opacity:0.7;">
<circle cx="6.5cm" cy="2cm" r="100" style="fill:red; stroke:black; stroke-width:0.1cm" transform="translate(0,50)" />
<circle cx="6.5cm" cy="2cm" r="100" style="fill:blue; stroke:black; stroke-width:0.1cm" transform="translate(70,150)" />
<circle cx="6.5cm" cy="2cm" r="100" style="fill:green; stroke:black; stroke-width:0.1cm" transform="translate(-70,150)"/>
</g>
</svg>

The patch is attached.

Thanks,
Trent