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

- Reset shift key when switching between layers

#744

- Fix hidden shift keys of numeric layout

#744

#744

- Distribute the math editor module to different files

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

This was changed without reason, but is actually a good (default) value.

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).

Disallow state variables without alias.

They are registered when being created.

#713

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

#703