Update version number.
Improvement: hidden courses can be shown depending on role in MIS.
New language strings added for new role capabilities.
Improvement: hidden courses can be shown depending in user role specified in MIS.
Fix bug: the 'Course (all years)' level is inferred but we don't determine if the course is visible or not.
Fix bug/improvement: if a course is hidden and the user doesn't have the capability of viewing it then the node for this course isn't included in the tree but the node's descendants must still be added.