referrer-policy attribute

Hi all,

we at Mozilla would like to finalise the implementation of the referrer
policy attribute but currently are blocked by the renaming issue. A pull
request has been submitted to the old github repo a while ago [1]. So it
would be awesome if a decision on this could be reached soon such that the
changes can make its way into the spec.

[1] https://github.com/w3c/webappsec/pull/435

Cheers,
Franziskus