Thumbnail/Preview support for WebDAV

Hi,

while listening to the working group discussion I realized that this 
feature can be implemented in WebDAV with almost zero cost; all that's 
needed is a single link-(set)-typed property; everything else can be 
handled through existing mechanisms, namely the ability to specify which 
metadata to retrieve (standard PROPFIND, RFC 2518/4918), + the ability 
to expand link targets upon lookup (REPORT + DAV:expand-property, RFC 3253).

Summary at: 
<http://lists.w3.org/Archives/Public/w3c-dist-auth/2009AprJun/0012.html>

I realize nobody asked for that, but this sort of illustrates that we're 
re-inventing things that may be much simpler over on the WebDAV side of 
the fence (and yes, I realize we're defining both an API and an HTTP 
binding here).

BR, Julian