- Use type 'no-value' as fallback value
- Send info also for state variables with type 'no-value'

- Replace top layer with inline editor
- Make keypad and keyboard available for TextAreaMath

1. Check if an alias is present, so that the constructor creates one.
2. Only register the value IDs, when creating a valid element. Invalid 
elements generate and register IDs in the constructor (else path).

They are registered when being created.

#713

This method is the same for all elements and can be implemented in the 
parent.

This may happen when changing the Clote document property.

Also move cloze-code into Cloze and no longer have it in a general 
purpose service.

The default value of the child class overrides the value set by the 
parent constructor.

#700

- Image
- Hotspot-Image
- Audio
- Video
- Geometry
- DragNDropValueObject (imgFileName, audioFileName)
- LikertRowElement (imgFileName, audioFileName)

Just ignore the color in the component.

- remove 'own' as possible connection

- remove 'none'