title: Offline iOS7 web app: doesn't update manifest
body: <p>I have written a web app for offline usage on iOS7 safari and, while it does download the files in the manifest for offline usage, it never updates cached files when the manifest changes.</p>
  
  <p>I have a php script that loops through files in a directory and creates a <code>cache.appcache</code> file. It also adds a comment that is a md5 of the files so that each time a file changes, the <code>cache.appcache</code> file will update.</p>
  
  <p>This works fine on desktop chrome and the app cache update is triggered. However, on the iPad it never tries to update the cache: I have to clear the device's cache manually to get the updated app.</p>
  
  <p>Is there something I'm missing?</p>