Oval radial gradients are broken

[jtothebell]

I have a couple swfs that use oval radial gradients, and they don't render properly. Here are a couple screen shots from SwiffDiff:

This is the SwiffCore rendering

This is the flash rendering

In my limited monkeying around, I discovered that if I switch line 531 of SwiffRenderer.m to use the AffineTransform's "c" instead of its "a" I get a circular gradient that is roughly the right size. I've no idea if that is just coincidence or not. The cirular radial gradients I tested had identical "a" and "d" values, but default values for "b" and "c".

If its helpful, the swf I used to take the screenshots can be downloaded here: https://dl.dropboxusercontent.com/u/4009158/testSwf/ovalGradientTest.swf

Thanks for your work on this project!