no cache for Page#show - load ajaxy changes - fixes #7849

ensure the page will be reloaded when navigated to in browser history
why? because we use a bunch of ajax on the pages - for example when
adding comments. It's really odd if these disappear when you navigate
back.
Merge pull request #117 from azul/bugfix/refresh-page

no cache for Page#show - load ajaxy changes - fixes #7849