Remove ParentID field from the fields

This should not be manually set by default.

code/model/Widget.php

@@ -155,6 +155,16 @@ class Widget extends DataObject {
 		return $this->renderWith('WidgetEditor'); 
 	}
 
+	/**
+	 * @return FieldList
+	 */
+	public function getCMSFields() {
+		$fields = parent::getCMSFields();
+		$fields->removeByName('ParentID');
+
+		return $fields;
+	}
+	
 	/**
 	 * @return FieldList
 	 */