Convex branch decomposition: add a flag to forbid middle links.

So as to comply to Icy track format.
Also changed the name to something more clear.
Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>
Convex branch decomposition: more tests for the non middle links case.

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>
ICYTrackFormatWriter: fix the embryo.

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