[#4571] for all files served out of mongo, add expires and last-modified headers, remove no-cache headers
[#4571] for all files served out of mongo, add expires and last-modified headers, remove no-cache headers

apache/incubator-allura,apache/allura,lym/allura-git,lym/allura-git,apache/incubator-allura,heiths/allura,apache/allura,heiths/allura,heiths/allura,heiths/allura,apache/incubator-allura,heiths/allura,apache/allura,lym/allura-git,apache/allura,lym/allura-git,apache/incubator-allura,apache/allura,lym/allura-git