Merge branch 'master' of github.com:celery/celery

CONTRIBUTORS.txt

@@ -169,5 +169,7 @@ Akexander Koshelev, 2014/08/19
 Davide Quarta, 2014/08/19
 John Whitlock, 2014/08/19
 Konstantinos Koukopoulos, 2014/08/24
+Albert Yee Wang, 2014/08/29
 Andrea Rabbaglietti, 2014/10/02
 Joe Jevnik, 2014/10/22
+Nathan Van Gheem, 2014/10/28