addcont: add user add-ons with --addcont and a launcher list

src/launcher/include/configurationListWidget.h

@@ -87,6 +87,7 @@ private:
 	QString                       m_runtime_directory;
 	QStringList                   m_game_dirs;
 	QString                       m_addons_dir;
+	QMap<QString, QStringList>    m_addcont; // User add-ons by title ID.
 	Configuration                 m_global_info;
 	QMap<QString, Configuration*> m_custom_infos;
 	CompatibilityDatabase*        m_compatibility = nullptr;