TrackMate_: remove useless methods and classes.

Most important changes: removed the subpixel package.
Sub-pixel is now handled to imglib2.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
TrackMate_: move interactive tests out of the main folder

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
TrackMate_: explicit generation of LoG kernels.

It seems like the clever filtering approach does not bring any benefits
below radiuses of 20 pixels, and let some border effect on the kernel.
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>