owned the area, add a warning in the area list of group if one of them
doesn't link to the course

OO-2043: add message under the toolbar is a course is freezed, better handler changes of status, reload course element by status changes...

OO-763: don't use the container as reference for collection of components but an interface instead, break the inheritence of Panel and flatted it

OO-291: implement the popup to manage the areas in a course, add first draft of the rights management