This function is behind the screen for adding new bans and modifying existing ones.
Adding new bans:
- is accessed by ?action=admin;area=ban;sa=add.
- uses the ban_edit sub template of the ManageBans template.
Modifying existing bans:
- is accessed by ?action=admin;area=ban;sa=edit;bg=x
- uses the ban_edit sub template of the ManageBans template.
- shows a list of ban triggers for the specified ban.