CDI extension needed by CDI Utils MVP-pattern. See https://github.com/tomivirkki/cdiutils/branches/vaadin and https://github.com/tomivirkki/cdiutils-addressbook/branches/vaadin7.
It hooks into CDI lifecycle listener afterBeanDiscovery. Goes through every AbstractPresenter Bean and adds an ObserverMethod which provides
1) transport for some own ParameterDTO as event object
2) making a qualifying filter from CDIEventImpl. CDIEventImpl is a public static class which extends AnnotationLiteral<CDIEvent>. CDIEvent is a ""Qualifier for view events observed by presenters." CDIEventImpl implements value(), whose value is set  to the value of the @ViewInterface on the Presenter Bean.
3) on notifyed with the ParameterDTO calling each targeted AbstractPresenter with viewOpened().