- Adds new sub-keys to replace key prefixes, and adjusts key names accordingly.
- Moves several button strings from `admin.permissions_` to `admin.permissions_controls`
- Merges `forum.settings_notify_` strings into `forum.settings`
- Rolls `forum.user_avatar_` strings into `forum.user`
- Moves the `user_deleted_text` to the `lib` namespace.
- Adds four other leftover strings to the `lib` namespace.
- Includes minor changes to formatting and comments.