Update jingo to 0.6 and run jingo.monkey.patch (bug 930512)

With the django 1.5 update suddenly form fields are being escaped in jinja.

* Looking at the jingo readme [1] there's a monkey patch in jingo that needs to be run. This was added in jingo 0.5.
* We are currently running 0.4.
* Also 0.6 specifically mentions django 1.5 support [2]

[1] https://github.com/jbalogh/jingo#forms
[2] https://github.com/jbalogh/jingo/blob/master/CHANGELOG#L22