Change Event Bus version to 0.0.4, fix message event handler

The message event handler ignored group messages, as event handlers do
not include subtypes be default. This behavior has been implemented in
Event Bus 0.0.4 and integrated into Envoy.

client/src/main/java/envoy/client/ui/controller/ChatScene.java

@@ -210,7 +210,7 @@ public final class ChatScene implements EventListener, Restorable {
 	@Event(eventType = BackEvent.class)
 	private void onBackEvent() { tabPane.getSelectionModel().select(Tabs.CONTACT_LIST.ordinal()); }
 
-	@Event
+	@Event(includeSubtypes = true)
 	private void onMessage(Message message) {
 
 		// The sender of the message is the recipient of the chat