Docs: Improve the return description for `wp_get_post_categories()` to include more information about possible return values.

Props jeherve for the initial patch.
Fixes #37002.

Built from https://develop.svn.wordpress.org/trunk@37686


git-svn-id: http://core.svn.wordpress.org/trunk@37652 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/post.php

@@ -2853,8 +2853,10 @@ function wp_untrash_post_comments( $post = null ) {
  *
  * @param int   $post_id Optional. The Post ID. Does not default to the ID of the
  *                       global $post. Default 0.
- * @param array $args    Optional. Category arguments. Default empty.
- * @return array List of categories.
+ * @param array $args    Optional. Category arguments. See wp_get_object_terms(). Default empty.
+ * @return array List of categories. If the `$fields` argument passed via `$args` is 'all' or
+ *               'all_with_object_id', an array of WP_Term objects will be returned. If `$fields`
+ *               is 'ids', an array of category ids. If `$fields` is 'names', an array of category names.
  */
 function wp_get_post_categories( $post_id = 0, $args = array() ) {
 	$post_id = (int) $post_id;

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-alpha-37685';
+$wp_version = '4.6-alpha-37686';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.