Fix error with the WYSIWYG and Greek characters

This commit aims to be a fix to the error with the WYSIWYG editor (TinyMCE) that not store properly non latin character (i.e. Greek letters). Solution comes from http://stackoverflow.com/questions/33043516/magento-greek-characters-as-html-entities

Author: Athanasios

lib/web/mage/adminhtml/wysiwyg/tiny_mce/setup.js

@@ -78,6 +78,7 @@ define([
             }
 
             var settings = {
+                entity_encoding: 'raw',
                 mode: (mode != undefined ? mode : 'none'),
                 elements: this.id,
                 theme: 'advanced',