A teacher can set one of 3 possible options for tracking read forum posts

NOTE: Student must have "Yes: highlight new posts for me" set for the 'Forum tracking' option in their profile

1. Login as a teacher and create a forum with 'Read tracking for this forum' set to Optional in the forum settings.
2. Login as a student and check you can choose whether to turn tracking on or off. The link to do this should be in the Settings block under Forum administration.
3. Login as a teacher and create a forum with 'Read tracking for this forum' set to Off.
4. Login as a student and check that read forum posts are not tracked and that you have no option to enable the feature.
5. Login as a teacher and create a forum with 'Read tracking for this forum' set to On.
6. Login as a student and check that read forum posts are tracked and that you have no option to disable the feature.