make [draw] arguments follow svg data spec

For path data commands, the last two parameters are always the x and y coordinate. But for [draw circle]/[draw rect]/etc. the arguments always begin with x and y coordinates. They should be changed to match the path data spec.

Not a big deal atm, but since nobody is using this API yet it should be changed now. It may become important later if we add a "clip-path" property using CSS shapes, because CSS shapes (roughly) follow the pattern of trailing coordinates.