CoreSession leak in case of HTTP Session Timeout

When the session timeout occurs, the Seam cleanup code is called in a thread that is not authenticated
=> the call to CoreInstance.getInstance.close() fails because of the underlying call to DocumentManagerBean.destroy that is not allowed ( EJB3 security interceptor blocks the unauthentciated call).

This result in a leak :

• We have a coreSession that is not released
  => static map in CoreInstance is not freed
  ==> may result in a OutOfMemoryError in PermGen
  => we leak an EJB3
  ==> one DocumentManagerBean passivated on disk that will never be cleared

Unless we find a clean way to bypass EJB3 security (since @PermitAll does nothing) the only walkaround is to open a SystemLogin.