TrackMate_: remove annoying debug messages

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
TrackMate_: make manual model annotation synchronized

In case where there is a tool that exploits multi-threading incremental
modification of the model.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
MaMuT_: make the semi-auto tracker abole to process several spots concurrently

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
MaMuT_: bump to v0.6.0

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
MaMuT_: rename the main class

Since it is not a PlugIn, it does not deserve the _ naming.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>