Simpler tree-algorithm

[Tuomas Lukka <lukka@xxxxxxxxxxx>]

AJ, here's one I'd like you to try at some point:

start with the current cell at a given point on the screen. Move to its
grandchildren, count number of grandchildren per child, and place the
children (shrunken accordingly) with such a ratio. Repeat, i.e. always
look two generations further for how to subdivide the space. Then, go two
steps upwards and show the siblings at both levels and, if space, their
children.

	Tuomas