Clarify that a Java EE component definition never results in a managed bean being created

Having e.g. a Servlet that matches managed bean requirements, there is nothing in the spec saying that the container should not take the servlet class and make a managed bean out of it. This results in ProcessInjectionTarget being fired twice. Furthermore, it does not actually make any sense to have Java EE component definitions (e.g. Servlets) to act as managed beans.