title: flask-cache memoize URL query string parameters as well
body: <p>The flask-cache extension has a <code>@cache.memoize</code> decorator to cache a view including the view's <code>*args</code> and <code>**kwargs</code>. Some of my views however take a URL query string as well, for example <code>/foo/image?width=640</code>. The decorator adds a <code>make_cache_key</code> method to the decorated view function that can be used to customise the cache key</p>
  
  <p>However I do not know how to get the <code>request.args</code> outside of the normal request context. </p>
  
  <p>Any ideas how to make the <code>@cache.memoize</code> work with URL query strings as well?</p>