title: Set cache-control for entire S3 bucket automatically (using bucket policies?)
body: <p>I need to set cache-control headers for an entire s3 bucket, both existing and future files and was hoping to do it in a bucket policy. 
  I know I can edit the existing ones and I know how to specify them on put if I upload them myself but unfortunately the app that uploads them cannot set the headers as it uses s3fs to copy the files there.</p>