Improve visualization of permissions

Improvements

• When starting to edit permissions then the user finds the list view by default, see screenshot-1. The user should find the graphical view by default, see screenshot-2
• In the graphical view a horizontal scrollbar should be added if the permissions tree doesn't fit to the window size of the browser.
• The graphical view for permissions should be the default view (as for all other views), currently the text view is the default view.