Fixes #10.
Fixes #10.

NSBezierPath for ellipses are now consistent with what happens with
other shapes: stroking the shape results in pixel-aligned output. Just
like with polygons, a filled ellipse needs to be rendered with both a
`fill` and a `stroke` on the corresponding NSBezierPath.

mobdim/ASCIImage,carelessGirl/ASCIImage,znatz/ASCIImage,cparnot/ASCIImage,zhouwude/ASCIImage