merge 2755 and 2756 from branch 2.0 to trunk

- 2755 fix vulnerability http://www.milw0rm.com/exploits/6755
- 2756 security paranoia: protect session/remember me cookies from XSS attacks (works only if php>=5.2 and with IE/FF maybe others)


git-svn-id: http://piwigo.org/svn/trunk@2757 68402e56-0260-453c-a942-63ccdbb3a9ee

include/ws_functions.inc.php

@@ -1187,17 +1187,9 @@ function ws_session_login($params, &$service)
  */
 function ws_session_logout($params, &$service)
 {
-  global $user, $conf;
   if (!is_a_guest())
   {
-    $_SESSION = array();
-    session_unset();
-    session_destroy();
-    setcookie(session_name(),'',0,
-        ini_get('session.cookie_path'),
-        ini_get('session.cookie_domain')
-      );
-    setcookie($conf['remember_me_name'], '', 0, cookie_path());
+    logout_user();
   }
   return true;
 }
@@ -1435,7 +1427,7 @@ function ws_categories_add($params, &$service)
   }
 
   invalidate_user_cache();
-  
+
   return $creation_output;
 }
 
@@ -1473,18 +1465,18 @@ function ws_images_exist($params, &$service)
     -1,
     PREG_SPLIT_NO_EMPTY
     );
-  
+
   $query = '
 SELECT
     id,
     md5sum
   FROM '.IMAGES_TABLE.'
-  WHERE md5sum IN (\''.implode("','", $md5sums).'\')  
+  WHERE md5sum IN (\''.implode("','", $md5sums).'\')
 ;';
   $id_of_md5 = simple_hash_from_query($query, 'md5sum', 'id');
 
   $result = array();
-  
+
   foreach ($md5sums as $md5sum)
   {
     $result[$md5sum] = null;