Localization: add a dummy solver, allowing skipping the curve fitting step

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Localization: update methods

- toString
- PeakFitter implements Benchmark
Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Localization: rework interactive tests

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Add .DS_Store to .gitignore

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>
Localization: A JUnit test for PeakFitter

Signed-off-by: Jean-Yves Tinevez <jean-yves.tinevez@pasteur.fr>