animation test: ellipse
Animation test of the specific attributes of the ellipse-element:
cx moves from left to right in 18s and freezes.
cy moves from top to bottom in 9s and repeats two times with repeatCount.
rx changes from small to big in 18s and freezes.
ry changes from small to big in 9s and repeats two times with repeatDur.
Gray shapes show some typical positions.