Add app::stop

libs/app/include/psemek/app/app.hpp

@@ -16,6 +16,7 @@ namespace psemek::app
 		~app() override;
 
 		virtual bool running() const;
+		virtual void stop();
 
 		void on_resize(int width, int height) override;
 		virtual void on_quit();

libs/app/source/app.cpp

@@ -94,6 +94,11 @@ namespace psemek::app
 		return impl().running;
 	}
 
+	void app::stop()
+	{
+		impl().running = false;
+	}
+
 	void app::on_resize(int width, int height)
 	{
 		gl::Viewport(0, 0, width, height);