[webappsec] New call-for-consensus on UI Security

<hat = editor>

I would like to issue new Call for Consensus to advance the latest editor's
draft of UI Security, found at:

https://dvcs.w3.org/hg/user-interface-safety/raw-file/d6c4917e3169/user-interface-safety.html

to Last Call Working Draft status.

Since the previous CfC, I have addressed comments about the definition of
the unsafe attribute, but the primary change is the removal of the
frame-options directive, which has been moved to CSP 1.1 as frame-ancestors.

As always, positive feedback is encouraged and silence will be taken as
assent.

This CfC will close 7 days from now, on March 25th, and we will review the
results on the regular teleconference the following day.

Thank you,

Brad Hill