fix bug 826456 - send review_tags to kumascript

https://bugzilla.mozilla.org/show_bug.cgi?id=826456

To test: add `<%= env.review_tags %>` to a KumaScript template used by a page. Then add/remove review tags to the page via the 'Technical' , 'Editorial', and/or 'Template' checkboxes. The template output should change to reflect the page's review tags.