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.

This is done within the element's logic.

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

#700

#700

It suddenly works without that. No idea why.

#702

This should allow users to notice, when errors happen and possibly 
report them.

It now uses the page index the menu (that was used to delete) belongs 
to, instead of the selected page index.

#707

#706

#702

#704

#705

This service is unused for a long time.

- concerns media elements

- functionality will be implemented later

Now the paragraphs are shown actually below each other and not next to.

#699

For automatic numbering of droplist items another node level 
(div-element) was introduced to the element DOM. Therefore this 
functions needs to look another node further up for it's position.

#694

Because there are more (pseudo-)tab on the (page-)tab pabel, the tab for 
the first page is no longer visible and can't be clicked. By increasing 
the viewport width, it becomes visible again.