ui: load source from directory via MenuBar

Added MenuBar action Project->New, which opens a directory dialog for choosing the new source directory to parse the
files from. The ConfigManager can be created empty now and setValue calls can be used to set values.

fortune cookie message = Your troubles will be faded by the luck you will soon have.

src/lib/Application.h

@@ -7,12 +7,15 @@
 #include "Project.h"
 #include "utility/messaging/MessageListener.h"
 #include "utility/messaging/type/MessageLoadProject.h"
+#include "utility/messaging/type/MessageLoadSource.h"
 
 class GuiFactory;
 class MainView;
 class Storage;
 
-class Application: public MessageListener<MessageLoadProject>
+class Application
+	: public MessageListener<MessageLoadProject>
+	, public MessageListener<MessageLoadSource>
 {
 public:
 	static std::shared_ptr<Application> create(GuiFactory* guiFactory);
@@ -20,11 +23,13 @@ public:
 	~Application();
 
 	void loadProject(const std::string& projectSettingsFilePath);
+	void loadSource(const std::string& sourceDirectoryPath);
 
 private:
 	Application();
 
 	virtual void handleMessage(MessageLoadProject* message);
+	virtual void handleMessage(MessageLoadSource* message);
 
 	std::shared_ptr<Project> m_project;
 	std::shared_ptr<Storage> m_storage;