= New Features

* An ip_from_header plugin has been added, which makes request.ip
  pull the IP address from a header if it is present. If you know that
  all requests are coming from a proxy, this is simpler and faster
  than attempting to parse the information out of the Forwarded or
  X-Forwarded-For headers.

* A hash_public plugin has been added, which operates similarly to
  the timestamp plugin plugin, but does cache busting based on the
  hash of the file content instead of the modification time of the
  file.  This is useful in containerized environments where the
  modification time of the file may change even if the content of
  the file does not.
