[fix bug 1183261] Upgrade to Django 1.4.21
[fix bug 1183261] Upgrade to Django 1.4.21

glogiotatidis/lumbergh,alexgibson/lumbergh,alexgibson/lumbergh,mozilla/lumbergh,chirilo/lumbergh,chirilo/lumbergh,alexgibson/lumbergh,chirilo/lumbergh,mozilla/lumbergh,alexgibson/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh,chirilo/lumbergh,ziir/lumbergh,ziir/lumbergh,ziir/lumbergh,glogiotatidis/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh,ziir/lumbergh