RTL for TinyMCE:

- Add _dir: 'rtl' to the TinyMCE translation object.
- Fix editor.css for RTL.
- Fix the Edit and Delete buttons position for wpview and images.
- For _mce_set_direction(), update documentation and fix adding the 'ltr' button.
Fixes #27773

git-svn-id: https://develop.svn.wordpress.org/trunk@28094 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-editor.php

@@ -982,6 +982,11 @@ final class _WP_Editors {
 		$baseurl = self::$baseurl;
 		$mce_locale = self::$mce_locale;
 
+		// Set direction
+		if ( is_rtl() ) {
+			$mce_translation['_dir'] = 'rtl';
+		}
+
 		/**
 		 * Filter translated strings prepared for TinyMCE.
 		 *