Fix ETags-based caching.
Our ETags-based caching has apparently been broken for a while. We've

been accessing an older form of the keys and not the "newer" normalized

form. This meant that our caching for review requests and other pages

weren't as effective.

Tested with a couple review requests. Verified that we could get the

If-None-Match header value in the request, compare against a review

request's ETag, and return a 304 Not Modified.