Merge branch '5.3' into 5.4

* 5.3:
  Fix section hierarchy in testing article

Author: wouterj

testing.rst

@@ -575,7 +575,7 @@ will no longer be followed::
 .. _testing_logging_in_users:
 
 Logging in Users (Authentication)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.................................
 
 .. versionadded:: 5.1