REST API: Add author, modified, and parent sort order options for posts.

These (and a few others that can be revisited later if needed) were present in
beta versions of the WP REST API but were removed during the merge to WP 4.7.

Props ChopinBach, jnylen0.
Fixes #38693.

Built from https://develop.svn.wordpress.org/trunk@40605


git-svn-id: http://core.svn.wordpress.org/trunk@40475 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php

@@ -2130,12 +2130,15 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 			'type'               => 'string',
 			'default'            => 'date',
 			'enum'               => array(
+				'author',
 				'date',
-				'relevance',
 				'id',
 				'include',
-				'title',
+				'modified',
+				'parent',
+				'relevance',
 				'slug',
+				'title',
 			),
 		);
 

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-40604';
+$wp_version = '4.8-alpha-40605';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.