Remove unnecessary publication check
Add ETag support for Post index page, part of #140
Add ETag support for Post show page, part of #140
Get rid of action caching now that we use ETags in Post controller #140
Separate caching of anonymous vs. admin users for Posts #140
Don't include CSRF tags on cacheable pages #140

As suggested by http://xyzpub.com/en/ruby-on-rails/3.2/http_caching.html