Blogware Trackback Autodiscovery

Brad has nailed down some niggly bits with Trackback Auto-discovery for Radio Userland blogs. As far as I can tell, we're fully interoperable now.
A general note about Trackbacks though - if you don't generate or include an excerpt, we're not sending it. Also note that we're not doing auto-discovery when you post via XML-RPC - this is temporary.