Filters are used for post-processing responses of HTTP responders.
A filter can read the responder's output, mofidy the response
headers and write a new response body.
The name under which a Filter is installed is interpreted as a
MIME type. All responses with that content type are processed by
||The current time in Greenwich Mean Time.
||The current time in the server's local time zone.
||The name of the resource that was requested by the client,
without path (i.e. the URL-decoded part of the Request-URI
between the last slash and an eventual option part).
||The URL-decoded Request-URI (without an eventual option part).
||The last modification date of the requested resource if available,