Cookieless cross-origin violation reports.

Consistent with the conversation in April's F2F, I've changed the 1.1 spec
to require that cross-origin violation reports are sent without cookies:
https://dvcs.w3.org/hg/content-security-policy/rev/788b0b653c39

I believe we'd reached consensus on that point, but I might have missed
some nuance over the phone. I'm happy to revert if there are objections.

--
Mike West <mkwst@google.com>, Developer Advocate
Google Germany GmbH, Dienerstrasse 12, 80331 München, Germany
Google+: https://mkw.st/+, Twitter: @mikewest, Cell: +49 162 10 255 91