Fix bug in main Sparse LAP tracker.

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

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>
Fien tune the integration of SparseLAPTracker.

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

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