TrackMate_: fix a bug in the side bar of TrackScheme

Some spots were NOT displayed in the side table of TrackScheme is
they were belonging to the same frame. That was because we relied on
TreeSet for the sorting. Now we use Collections.sort(List).
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
TrackMate_: bump to version 2.0.2
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>