Fixing xml schema generation for code completion in ides

lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php

@@ -53,7 +53,7 @@ class XmlExporter extends AbstractExporter
 
         $xml->addAttribute('xmlns', 'http://doctrine-project.org/schemas/orm/doctrine-mapping');
         $xml->addAttribute('xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance');
-        $xml->addAttribute('xsi:schemaLocation', 'http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd');
+        $xml->addAttribute('xsi:schemaLocation', 'http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd');
 
         if ($metadata->isMappedSuperclass) {
             $root = $xml->addChild('mapped-superclass');