#490650 by litwol, JirkaRybka, nbz, Berdir, Liam McDermott: Message to oneself AND aditional recipients remains as unread forever. This patch fixes this behavior moving forward as well as providing update hook to update old messages that were affected by this issue.

#441042 by Berdir: Replace multi-select list of users in filter form with a more performant autocomplete-text-field

#404960 by Berdir: messages/view/% shows the participants of a conversation even if there are no messages that the user can view.

#436946 by Berdir: Bugfix for PostgreSQL: PostgreSQL doesn't allow to reference subqueries with alias in HAVING

#376023 by Berdir + bugfix by litwol: #288183 followup: change hook_privatemsg_block_message to work on multiple recipients