Code style changes.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Make the ImagePlusChooser more reusable.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Make the loading plugin more reusable.

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
An importer for ICY track XML files.

Just point the TrackMate loader to an ICY tracks XML file, and it will
do the loading. All available features will be re-calculated on loading.
You also need to specify a target ImagePlus.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>