shadow of voronoi graph

* added getRadius to obstacles, for general size estimation
* polygons can remove ignored points in their constructor, re-order to
be clock-wise complete even for non-closed convex shapes, and draw
filled in non-closed shapes (makes an open-mouthed pac-man shape towards
open edge)
* added GL/freeglut to v2.h, to stop those weird #include problems. man,
C++ still has some problems...
* cleaned up delauny.h a bit. starting to make random-graph API.
* made voronoi editing not-a-thing, but it will be-a-thing again if
delaunyEdit is set to delauny in game.