adding rtfd content-type?

[William Shipley]

> http://myhost.domain/~me/doc.rtfd spins indefinitely

Well, I wouldn't expect it to spin forever, but it also isn't going to  
work.  The way an RTFD document works is there are all these little fiddly  
images inside the directory with the TEXT.rtf, and we'd have to basically  
special-case rtfd so that it downloaded all the files inside the directory  
and then opened the actual RTF file.  Otherwise, the images wouldn't show  
up.

We may do this kind of thing in a general way so downloading file packages  
is possible (we've had requests for being able to click on .diagram files),  
but we haven't yet.

-Wil