Configuration and implementation to allow the users to request the
deletion of their account if they don't accept the disclaimer or in
their settings under the disclaimers.

Implement relation between identities with a configurable role,
administration to manage the roles, and the relations in user
management.

Move the functions of OlatRootFile and OlatRootFolder to the Local
implementations to simplify the use of VFS, implements factory methods
in VFSManager, reduce the number of call to meta informations in folder
listing