Before, we only had buttons for assigning and unassigning topic on
the topic level assign menu. This commit adds dynamic buttons for
unassigning posts to the menu.
Ability to assign groups.
To assign group, user must have a right to send a message to that group.
In addition, 2 jobs were introduced, - AssignNotification and UnassignNotification to inform interested users in the background about the new assignment.
Andrei Prigorshnev
Rafael dos Santos Silva
Jarek Radosz
Joffrey JAFFEUX
Ahmed Gagan
romanrizzi