Add new "Input Image" panel in the left side of the GUI.

First attempt to try to make the GUI cleaner for non-expert users.
Redo segmentation panel to incorporate new suggestions.

Now the dynamic is called "tolerance" and the dams option is under advanced options.
Enable/disable gradient components when selecting object image type.
Change segment button text to "Run"
Enable/disable components in a consistent way after running the segmentation pipeline.
Add tool tip texts to radio buttons.
Read gradient radius from user input.
Add code to allow displaying gradient image in main canvas.
Update comment
Reorganize result display panel.

- Rename it as "Results".
- Replace the toggle button by a check box.
- Replace the "Show" button text by "Create Image".
Make "Create Image" button of minimum size.
Remove empty lines.
Center radio buttons in input image panel.
Make output image equal to the displayed image.
Add comments to clarify code.
Make sure output image takes the gradient image when it is displayed.
Resize segmentation button to display "STOP" correctly.
Beautify code.
Create overlay image on the fly.

That allows taking into account the gradient image when present.
Remove output image code, no longer needed.