[Gzz] Buoy layout

[Tuomas Lukka]

Heh, I finally figured out an easy way to lay out buoys.

And it fits together extremely well with the nadir idea.

Quite simply, pick a point and project from the anchor to a circle
(all buoys are on the same circle).

If buoys are nondirectional, the point would be the center, if directional,
two different points left and right of the circle. This creates two 
families of lines, which the human eye can deal with easily, much
better than with random, conflicting directions.

The buoys will overlap but that will be handled by the priority
mechanism: they rise and fall by distance to center or somesuch.

        Tuomas