Introduce a script component question background color.
Add more feedback for the analyze experiment component.

- The experiment check box is only ticked when the analyze has been
performed successfully.
- Show a position graph in the script component fragment.
Add ScriptComponentQuestion, refactoring and visual improvements.

- Add a general purpose counter to the sheet component.
- Add a question component that uses such a counter to display text,
e.g. "Q4: ...".
- Move the core part of the ScripComponentTreeSheet into a separate
class.
- Set background color of the check box and the question component.