Change dimensions of y-axis when plot is normalized.

Remove y_min limit.
Add a reset button.
Canceling file dialog do not erase textbox.
Change name of configuration file.
Remove unecessary comments.
Merge branch 'master' into GUI
Change in order to use the new class s4.utils.JSON created.
Make plot title prettier.
Merge branch 'master' into GUI
Fix bug due to change in Radial velocity correction procedure.