@robhudson: line 65/66 is only present for calls to `reverse('browse.creatured')`.
A call to _/extensions/my-category/?sort=featured_ still matches `^extensions/(?P<category>[^/]+)/$` from [line 56](https://github.com/mozilla/zamboni/blob/master/apps/browse/urls.py#L56), as it does without this PR and refers to the right view (`views.extensions`).