flex-start is the correct value for flex containers.

Measure holds the value and a unit for CSS properties.

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

- Reformat styles

For all other input assistance presets, the status of the backspace key
is fixed.

- There is a page navigation only for not always visible pages
- Fix initialization of the button's action parameter

- allowReplacement (moved from element to list prop)
- originList and Index are non-optional (means placeholders have to be 
used sometimes)
- Re-introduced the dict of all DropListComponents. This is the only way 
I have found to get a reference to a DropListComponent by ID. This is 
needed for returning to origin. Origin is not actually part of the 
transaction and needs to be fetched from somewhere else. Hence the dict.

- Console statements still present for debugging.

The native browser-drag-and-drop does not work in tablets. Therefore 
back to Material which works.
Features are moved over with the exception of replacing items.

- Copy-Lists now always allow putting items back.

- Renew example files
- Update versions and notes