src: Various fixes from testing

* fixed deleted project could still be selected in the recent project menu
* fixed project file not loaded when declining for reload
* fixed main in tutorial description not clickable
* fixed clang warnings
* fixed commands not showing up in autocompletion
* fixed classes were expanded when activating aggregation
* fixed crash when messagelisteners tried to unregister after messagequeue was destructed

src/lib/utility/messaging/MessageQueue.cpp

@@ -20,7 +20,12 @@ std::shared_ptr<MessageQueue> MessageQueue::getInstance()
 
 MessageQueue::~MessageQueue()
 {
-	// TODO: remove remaining listeners. And tell them that they shouldn't unregister anymore.
+	std::lock_guard<std::mutex> lock(m_listenersMutex);
+	for (size_t i = 0; i < m_listeners.size(); i++)
+	{
+		m_listeners[i]->removedListener();
+	}
+	m_listeners.clear();
 }
 
 void MessageQueue::registerListener(MessageListenerBase* listener)