attempt to implement and make use of the tree-side drag and drop; does not work out-of-the-box, at least not as attempted in mail module

etemplate/js/et2_widget_tree.js

@@ -490,6 +490,39 @@ var et2_tree = et2_inputWidget.extend(
 		return this.input.hasChildren(_id);
 	},
 
+	/**
+	 * enableDragAndDrop
+	 *
+	 * @param _mode boolean
+	 * @param _rmode boolean
+	 */
+	enableDragAndDrop: function(_mode, _rmode) {
+		if(this.input == null) return null;
+		return this.input.enableDragAndDrop(_mode,_rmode);
+	},
+
+	/**
+	 * setDragBehavior
+	 *
+	 * @param _mode string
+	 * @param _smode boolean
+	 */
+	setDragBehavior: function(_mode, _smode) {
+		if(this.input == null) return null;
+		// only supported by professional edition of dhtmlXTree
+		//return this.input.setDragBehavior(_mode,_smode);
+	},
+
+	/**
+	 * enableDragAndDropScrolling
+	 *
+	 * @param _mode boolean
+	 */
+	enableDragAndDropScrolling: function(_mode) {
+		if(this.input == null) return null;
+		return this.input.enableDragAndDropScrolling(_mode);
+	},
+
 	/**
 	 * Callback for after using dhtmlxtree's AJAX loading
 	 * The tree has visually already been updated at this point, we just need