remove all array_push (50% slower than []) + some changes missing for feature:2978

git-svn-id: http://piwigo.org/svn/trunk@25018 68402e56-0260-453c-a942-63ccdbb3a9ee

include/ws_protocols/rest_encoder.php

@@ -66,7 +66,7 @@ class PwgXmlWriter
     }
     $this->_output( '<'.$name );
     $this->_lastTagOpen = true;
-    array_push( $this->_elementStack, $name);
+    $this->_elementStack[] = $name;
   }
 
   function end_element($x)