title: How to make .mo files available to Google App Engine?
body: <p>Trying to run webtrees (<a href="https://github.com/fisharebest/webtrees" rel="nofollow">https://github.com/fisharebest/webtrees</a>) on GAE. Can't get GAE to recognise .mo compiled language files. The app works OK locall via GAE SDK.  I declared them as:</p>
  
  <pre><code>- url: /language/(.*.mo)
    mime_type: text/plain
    static_files: language/\1
    upload: language/(.*.mo)
    application_readable: true
  </code></pre>
  
  <p>I can download all .mo files OK via URL, but function in I18N.php to test which .mo files are available returns null. I'm wondering why GAE doesn't see the files even though I selected "application_readable"?  Is there an issue with declaring .mo files in GAE? I noticed a mime type error on first attempt, so added the mime_type declaration.</p>