Implement legacy forge button!

Many refactors of the task system.
Progress dialog now accepts generic ProgressProvider objects

gui/OneSixModEditDialog.h

@@ -40,6 +40,7 @@ private slots:
 	void on_viewResPackBtn_clicked();
 	// Questionable: SettingsDialog doesn't need this for some reason?
 	void on_buttonBox_rejected();
+	void on_forgeBtn_clicked();
 protected:
 	bool eventFilter(QObject *obj, QEvent *ev);
 	bool loaderListFilter( QKeyEvent* ev );