Implement #545

* Instance group can be selected when creating and copying instances
* Original group is pre-selected when copying
* Last used group is pre-selected when creating new instances

gui/dialogs/NewInstanceDialog.h

@@ -39,6 +39,7 @@ public:
 	void loadVersionList();
 
 	QString instName() const;
+	QString instGroup() const;
 	QString iconKey() const;
 	BaseVersionPtr selectedVersion() const;