title: carrierwave: point to existing image
body: <p>In my rails app, I'm using Carrierwave to upload images on Amazon S3.  I'd like to point to existing Amazon S3 images without having to re-upload the image.  For example, if I have an existing Amazon S3 image at <strong><a href="http://test.s3.amazonaws.com/image/path/0001/image.jpg">http://test.s3.amazonaws.com/image/path/0001/image.jpg</a></strong>, can I update an image's path to point to this image?  I don't want to use the remote upload option because I really just want to use the same exact image that's already there (but save it in my record's "path" attribute).</p>
  
  <p>In the console, I've tried:</p>
  
  <pre><code>image.update_attributes(:path=&gt; "http://test.s3.amazonaws.com/image/path/0001/image.jpg")
  </code></pre>
  
  <p>but this fails to override the image's path.</p>