Working dialog and new parameter: smoothing window.

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>
Exploit a simple moving average when thresholding on velocity.

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>
Compute and store track features related to velocity thresholding.

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>