Add option not to show private courses in the courses catalog
Although it is impossible for students to subscribe to them, private courses appear in the courses catalog.
Add a configuration setting $_configuration['course_catalog_hide_private'] = 'true'; (false by default) that, when set to true, hide the private (and closed) courses from the courses catalog.
This also implies changing the categories tree to only show the number of courses that are open or public.
As for all temporary setting (that don't go into the database because of the Chamilo version), this setting must be added (in git) to main/install/configuration.dist.php with a little explanation:
// Hide private courses from course catalog
// $_configuration['course_catalog_hide_private'] = 'true';