TrackMate_: added code style for Eclipse code formatter.
TrackMate_: minor changes to Eclipse formatter

I don't like empty declarations to take space.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
TrackMate_: add a method in semi-auto tracking to expose new spot

So that subclassers can hook to it.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>