New Web Service mod_forum_view_forum_discussion

Note: Version number is bumped because a new web service is added into the Mobile app service and to the forum list of external functions.

1. Create a course with a student,.
2. Create a forum activity, as student or admin create a discussion with a couple of replies (you will need the discussion id later).
3. As admin or teacher, go to the Course logs and check that there are log entries for the "Discussion viewed" event with origin "web"
4. As admin, enable "Mobile services": Plugins ► Web Services ► Mobile
5. Create a Token for the student user
   • Click on Site administration ► Plugins ► Web services ► Manage tokens
6. Next, you can do a CURL REST call simulating a WS client with the student user .
   • You need to replace the wstoken, discussionid (the discussion you created id value) and the URL of your moodle instance

     curl 'http://localhost/m/stable_master/webservice/rest/server.php?moodlewsrestformat=json' --data 'discussionid=16&wsfunction=mod_forum_view_forum_discussion&wstoken=ffbe3a3002f235bf9d01fd9369e10b66'

7. Confirm that
   • You can see new entries in the course log (Discussion viewed) for that course, the user and the forum. The origin for the new log entries is "ws"
   • If you use an invalid discussion id you will get errors