Possibility to deactivate reasons in administration (lectures)

It should be possible to set the reasons ("Reasons lectures" AND "Reasons absences") in the administration interface for lectures to "inactive". This is done via Status active/inactive.

If a reason is marked as inactive, it can no longer be used as reason in lecture roll-call by the coach or as reason for an absence for future lectures. However all previously collected data is still available for i.e. export and display in the user interface.

Implications of "Reason lectures" set to inactive - it can not be longer used for new entries:

• Coach-view of a lecture detail (/lectures/0/LectureBlock/)
• Lectures management -> lecture detail (LecturesManagementSite/0/Teacher/0/LectureBlock/)
• Coaching tool (/CoachSite/0/Lectures/0/Teacher/0/LectureBlock/)

Implications of "Reasons absences" set to inactive - it can not be longer used for new entries:

• Coaching tool -> absences / notice of absences
• Lectures management -> absences / notice of absences
• Personal view of student -> "Record new notice of absence" (/mylectures/0)