title: HttpServletRequest getLocale returns OS locale not browser locale
body: <p>I am using vaadin framework and in my application I have:</p>
  
  <pre><code>@Override
  public void onRequestStart(HttpServletRequest request,
          HttpServletResponse response) {
      currentIP = request.getRemoteAddr();
      setLocale(request.getLocale());
      handle.set(this);    
      this.request = request;    
      this.response = response;
  }
  </code></pre>
  
  <p>however, request.getLocale() returns <code>en_US</code>, which is my OS locale. However, in Firefox addon for switching locales (<a href="https://addons.mozilla.org/cs/firefox/addon/quick-locale-switcher/?src=userprofile" rel="nofollow">https://addons.mozilla.org/cs/firefox/addon/quick-locale-switcher/?src=userprofile</a>), I have set up it to be <code>cs_CZ</code>, however, getLocale() will still return <code>en_US</code>.</p>