[karl-bullock]

The Realtime admin page (from #598, mine) covered the websocket server and its config.php options, but not the extension's own settings or permissions. This adds both.

• Settings: all six, with their defaults: the typing indicator, discussion-list typing dots (and the restricted-tags variant), discussion list updates and their interval, and the notification toast duration. Also the Display who is typing preference that members with the permission get on their own Settings page.
• Permissions: View who is typing (View section; can be given to guests and granted per restricted tag) and See who is typing anywhere on the forum (Moderate section, used by Deck's Typing activity column). Neither is granted to any group by default.

Checked against the extension's source and on a stock 2.0.0 forum running the realtime server, with two members in separate sessions:

• Without View who is typing, a member sees no typing indicator and has no Display who is typing preference. With it, they see "bob is typing" and get the preference.
• The discussion list shows "1 discussion has updated activity and will be released in 7 seconds. Click to show now." and updates itself when the countdown ends.