New config option to show/hide list of all groups and list of other resource types

In the repository site all users can list all courses. In larger systems this just does not make any sense and on the other side this feature is a real resource hog (memory, db queries etc).

Two new config options are introduced:

repo.listallcourses.enabled=true
repo.listallresourcetypes.enabled=true 

Both values are set to true by default.

When repo.listallcourses.enabled=true, the list of all courses are show as it is today. When false, the menu item does not show up.

When repo.listallresourcetypes.enabled=true and the user is author, all other resource types appear as separate menu items. When set to false, the menu items are not show to any user.