Introduce is_rtl(). Use it in core. It only becomes defined when locale is loaded, so it's impossible to use it too early. Deprecate the get_bloginfo('text_direction') call. fixes #13206.

git-svn-id: https://develop.svn.wordpress.org/trunk@14360 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/js/tinymce/wp-mce-help.php

@@ -128,7 +128,7 @@ wp_admin_css( 'wp-admin', true );
 		border-bottom: 0px;
 	}
 </style>
-<?php if ( ('rtl' == $wp_locale->text_direction) ) : ?>
+<?php if ( is_rtl() ) : ?>
 <style type="text/css">
 	#wphead, #tabs {
 		padding-left: auto;