Replace OpenStack LLC with OpenStack Foundation

Some files still use trademark OpenStack LLC in header, which
should be changed to OpenStack Foundation.

NOTE: tools/install_venv.py is not synced from oslo-incubator, so
it is modified too.

Change-Id: I0084684ff5225076291fea857eb010d638291bd0
Fixes-Bug: #1214176
diff --git a/tools/install_venv.py b/tools/install_venv.py
index f37e0cd..84d0fd9 100644
--- a/tools/install_venv.py
+++ b/tools/install_venv.py
@@ -4,7 +4,7 @@
 # Administrator of the National Aeronautics and Space Administration.
 # All Rights Reserved.
 # flake8: noqa
-# Copyright 2010 OpenStack, LLC
+# Copyright 2010 OpenStack Foundation
 # Copyright 2013 IBM Corp.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may