Use an opt-out flow for comments in video, springify notifications and
notifications handlers

OO-3295: update hibernate to version 5.3 (JPA 2.2), infinispan 9.2 and use the new streaming API in some key queries

OO-2974: implement a way to understand different identifiers per page (classic page name, initial page name, old page names)

OO-2844: add option to show the full text search to guest users, update check access of the different indexers, remove the context aware full text search in forum if the option is disabled

OO-2837: add the possibility to lazy load tabs in the tabbed pane and use it for business group administration and user overview

OO-2043: add message under the toolbar is a course is freezed, better handler changes of status, reload course element by status changes...

OO-2097: fallback for files with underscore, and special case  for files with underscore and special characters

OO-1770, OO-1769: allow pseudonym and guest posts, refactor the message model to hold only threads or messages of a unique thread in memory, minimize the number of joins on query, minimize the number of queries on peekview, remove buggy docking feature...

OO-1198: set the pageId in the main controller after every page selection, with the menu, the history...

OO-1068: fix tooltip on link, add number of entries in table, hardened business control against null resource

OO-763: don't use the container as reference for collection of components but an interface instead, break the inheritence of Panel and flatted it

OO-568: fix memory leak, remove inner class to prevent big memory consumption if an other memory leak...