Require the latest Django 1.4.11 security release.

This fixes a number of security issues. Most importantly to us, a bug in
reverse() that could lead to importing unexpected modules, if the
attacker knows which modules are on the server.

See https://www.djangoproject.com/weblog/2014/apr/21/security/
Release Review Board 1.7.25.
Merge branch 'release-1.7.x' into release-2.0.x