title: AWS::S3::S3Object.url_for - How to do this with the new AWS SDK Gem?
body: <p>I've been using this forever with paperclip and aws-s3:</p>
  
  <pre><code>  def authenticated_url(style = nil, expires_in = 90.minutes)
        AWS::S3::S3Object.url_for(attachment.path(style || attachment.default_style), attachment.bucket_name, :expires_in =&gt; expires_in, :use_ssl =&gt; true)
    end
  </code></pre>
  
  <p>The new paperclip uses the AWS-SDK gem, which breaks this giving the error:</p>
  
  <pre><code>undefined method `url_for' for AWS::S3:Class
  </code></pre>
  
  <p>Anyone know how to get this method to work with the new AWS-SDK gem?</p>