Allow moderators and administrators to be warned.
AdminCP access can obviously bypass any warning issued, and warnings themselves can be edited or deleted depending on permissions for the user.
Introduces 7 new permissions:
- Give moderators warnings directly.
- Give administrators warnings directly.
- Delete all warnings for Moderators.
- Delete all warnings for Administrators.
- Prevent posts being warned.
- Prevent being directly warned.
- Prevent profile posts being warned.
Requires between 0 or 1 extra queries depending on if the active members on the content to-be-warned share a permission combination group with the visitor.