• [config] Fix api empty IP list
• [groupmembership] Faster loading time
• [groupmembership] Red labels for empty schoolclasses
• [groupmembership] Remove recursiv search of members, display groups
  instead
• [groupmembership] Sort schoolclasses
• [session] Faster loading time for groups list
• [users] Catch errors when printing passwords
• [users] Hide empty schoolclasses in password view
• [users] Sort schoolclasses in password view