user avatar in public feed activity:subject

lib/diaspora/ostatus_builder.rb

@@ -53,6 +53,7 @@ module Diaspora
   <id>#{@user.public_url}</id>
   <title>#{@user.real_name}</title>
   <link rel="alternative" type="text/html" href="#{@user.public_url}"/>
+  <link rel="avatar" type="image/jpeg" media:width="100" media:height="100" href="#{@user.image_url}"/>
 </activity:subject>
       XML
     end