Fix 'closed' parameter for pagination links.
Fix 'closed' parameter for pagination links.

Currently, if you go to e.g. http://codereview.appspot.com/ and click "Open",
it takes you to:

http://codereview.appspot.com/all?closed=0

Then, if you click on "Older", it will be this URL:

http://codereview.appspot.com/all?limit=10&closed=False&offset=10

This changes the above to have closed=0 instead of closed=False, which makes it
actually work.

Original Author: Alexei Svitkine <asvitkine@chromium.org>

Review: http://codereview.appspot.com/5562046/

ligthyear/quick-check,ligthyear/quick-check