Add DeadEvent

A dead events wraps an event that was dispatched but not delivered to
any handler. The dead event is than dispatched to dedicated handlers.

@@ -0,0 +24,4 @@
+	}
+
+	/**
+	 * @return the event bus that originated this event

@@ -82,2 +76,2 @@
-				handler.execute(event);
-			}
+		Iterator<EventHandler> handlers = getHandlersFor(event.getClass());
+		if (handlers.hasNext()) {

@@ -84,0 +83,4 @@
+				} else {
+					handlers.next().execute(event);
+				}
+		} else if (!(event instanceof DeadEvent)) {

@@ -99,3 +111,3 @@
 
 		// Get handlers defined for the event class
-		Set<EventHandler> handlers = bindings.getOrDefault(eventClass, new TreeSet<>());
+		TreeSet<EventHandler> handlers = bindings.getOrDefault(eventClass, new TreeSet<>());