Kymograph view has now an overlay and a mouse wheel listener.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Kymograph overlay now displays tracks.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
The profile plot now displays spots.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
The profile plot now displays tracks.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>