Circle.fromSVGPath does not need an nsResolver as parameter anymore. Instead it takes an optional parameter that can be used to allow rx != ry cases (and just take (rx+ry)/2 as radius)
fixed two bugs: 1) corrected calculation of sampling error for splines 2) cloneNode instead of copyNode in Polygon.renderInSvg method. 3) new method: Polygon.fromSVGRect
show error margin in the visual-path-test demo