API CHANGE: A DataList can be passed as the 2nd argument to the constructor; this is the recommended approach for editing non-relations.
API CHANGE: You can't set a custom query; only a custom DataList.
API CHANGE: You can't have one of these fields editing data that doesn't correspond to a DataList - there must be some kind of DataObject behind it.
API CHANGE: If the field's name corresponds to a relation on the object being edited, then the relation is used as the data set - all the source* parameters are ignored.
API CHANGE: relationAutoSetting only works if your form has had the corresponding data object loaded with $form->loadDataFrom().
API CHANGE: relationAutoSetting can't be turned off; attach a non-relation DataList instead.
