Media: Add `aac` to the list of allowed file types.

Props desrosj.
Merges [42697] and [43135] to the 4.9 branch.
Fixes #42919.
Built from https://develop.svn.wordpress.org/branches/4.9@43136


git-svn-id: http://core.svn.wordpress.org/branches/4.9@42965 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/functions.php

@@ -2446,6 +2446,7 @@ function wp_get_mime_types() {
 	'dfxp' => 'application/ttaf+xml',
 	// Audio formats.
 	'mp3|m4a|m4b' => 'audio/mpeg',
+	'aac' => 'audio/aac',
 	'ra|ram' => 'audio/x-realaudio',
 	'wav' => 'audio/wav',
 	'ogg|oga' => 'audio/ogg',

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9.6-alpha-43134';
+$wp_version = '4.9.6-alpha-43136';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.