[Gzz] jvk: irregu

[Tuomas Lukka]

Jvk, could you see if you could implement a renderable that makes
an ellipse (or possibly also superellipse i.e. degree other than 2)
of the new irregu code, given 

cs1: frame to screen
cs2: "virtual paper" to screen

Here, the complicated logic of the other irregu is not needed, since there
are no paper edges.

        Tuomas