Media elements needs time to load and change the dimensions of the page

#441

Replace the assignment of the ElementComponent with the assignment of
a ElementComponent that will work in future versions of Angular

Displaying a message is task of the host
#398

- Prepare usage in editor
- Remove test from ScrollPagePipe, because the call to "new Page" expected
  the initialization of GeometryComponent

- Remove css margins of floating keypad

- A floating keypad is generated inside a div with the class
  'cdk-overlay-pane'. Now the position of this div is updated when
  dragging the keypad.

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

- Add cdk scrolling strategy to keyboard that brings overlays to
scrolling

- Set the duration of highlighting anchors to 15 seconds
- Disable simultaneous highlighting of anchors