Release version 2.4.3

This release fixes a performance issue on session creation affecting
large installations.

Bug fixes:
* WebSocket communication now works correctly for course sessions.
  (only affects installations using the LMS connector)
* The configuration parameter `security.facebook.allowed-roles` is now
  respected.

Additional changes:
* Libraries have been upgraded to fix potential bugs

Release version 2.5.1

This release fixes a performance issue on session creation affecting
large installations.

Bug fixes:
* Session import works again.

Additional changes:
* Libraries have been upgraded to fix potential bugs

Release version 2.5.2

This is a maintenance release which only brings libraries up to date to
fix potential bugs.