Merge branch '5.2' into 5.x

* 5.2:
  added missing gitattributes and gitignore
  allow CurlHttpClient on Windows
  [Security] Mark ExpiredLoginLinkStorage as experimental
  remove references to "Silex"

Author: derrabus

Session/Storage/MockFileSessionStorage.php

@@ -113,9 +113,8 @@ public function save()
             $this->data = $data;
         }
 
-        // this is needed for Silex, where the session object is re-used across requests
-        // in functional tests. In Symfony, the container is rebooted, so we don't have
-        // this issue
+        // this is needed when the session object is re-used across multiple requests
+        // in functional tests.
         $this->started = false;
     }