coordinate mapping from SVG paths to SDL doesn't position objects correctly

[scottwalters]

One Zemmings::SVG::Object is created for each path found in the SVG level source being loaded. Each object contains a shape and a body. SVG paths pretty well correspond to objects. They each have a color and so forth, and can be filled. Each Box2D polygon shape created from the SVG paths looks pretty correct, but their position relative to each other is wrong (or looks wrong). There's some cropping and scaling code in there that might be the problem, or the problem might be related to parsing SVG's wonky command language for paths, documented at http://www.w3.org/TR/SVG/paths.html#PathData.