bug #4783 : The concrete contents implement now the new method canBeAccessed().
For the majority, they just ask the ComponentAccessController if the specified user can access the Silverpeas application that manages them.
For those that use the PublicationDetail as their underlying content, their implementation belongs to the PublicationDetail one. In this implementation, the access rights are verified both on the application itself and on the nodes in which the publication is in (when there is a node).
bug #4783 :  The access to a given scheduled event by a user is now checked from both the author and the contributors of the event. A fix is also done to avoid the direct access to an event by an unauthorized user with its URL; the 404 error page is then displayed (instead of this stupid and unuseless exception trace)