Create methods for managing permissions in the collection model.
Add CurrentUserMiddleware to get current user from everywhere.
Add implementation of the 'News'-tab.
Change timezone to Europe/Berlin
Bugfix: Wrong user who did the action under 'News'-tab.
Bugfix: Display files in tab 'My shared folder'.
Add implementation of the public view.
Add line breaks in some descriptions in the web view.
Bugfix: Filter subscribed collections under tab "Retrieve new collections".