[widgets] Widget Updates

We've been working on getting the Widget Updates specification in to
publication shape over the last few weeks and it would be good to get
further review of the current specification with a view to pushing it to
Last Call.

The latest draft of this specification can be found here:

http://dev.w3.org/2006/waf/widgets-updates

We've added the ability for developers to signal that their widget is at
end-of-life, signalling to the user agent to disable and/or uninstall the
widget when an 'HTTP 410 Gone' message is received in response to querying
the Update Description Source for a new Update Description Document. This
response can optionally contain the Update Description Document indicating
the reason for end-of-life within the details tag for the user agent to
display or log as required.

All feedback is welcome on this list.

- Rich