[TYPO3-dam] Creating a new user with all categories is very difficult.

[Andreas Balzer]

Hi!
I would like to create a new user and give him the possibility to modify 
  and work with every dam category. This should include categories that 
are not created at the time, when the user is created. The problem: I 
can not select 'Categories' when chosing a DAM mount point. Is it 
possible to somehow use that root?

Greetings
Andreas