[Gzz] Irreguframe (attn: jvk)

[Tuomas Lukka]

Still one more problem with dicing in irregularframe: when distorted
and when we're at the edge of the rectangle, there are bad artifacts because
the triangles are long and don't get distorted. What I mean is when the
edge of the paper from which the tearout is made is curved, the edge
drawn by IrregularQuad is not.

One solution would be to dice the whole interior but that would probably be too 
slow.

What do you think, should we handle the edges explicitly or something?

This problem occurs at the transition from the tearout buoy to the central 
zoomed paper
where we in the end contain the whole paper in the tearout (I hope this won't 
kill
our frame rate).

        Tuomas