animation test: path
animate test of a specific attribute of the path-element:
d (represented by a blue curve)
moves from the dark gray curve to the light gray curve in 10s.
d contains the commands M, m,l, L especially to test different
combinations of M/m commands.
For comparison an animateTransform of a red path is provided,
due to the specific choice of the path data, this has the same visual
effect. The blue path has to cover the red path completely.
If something red gets visible, an error is occured.