Form submit handler for node_form().
This submit handler needs to run before entity_form_submit_build_entity() is invoked by node_form_submit_build_node(), because it alters the values of attached fields. Therefore, it cannot be a hook_node_submit() implementation.
function locale_field_node_form_submit($form, &$form_state) {
locale_field_entity_form_submit('node', $form, $form_state);
}