Serialization for D. Comments, please!

[BCS]

And yet more progress. This time I've got "hard-links" working and I'm thinking 
about how to do 3rd party types.

I don't have any useable ideas I really /like/, but I have one I'm sure I 
can make work. I do have one idea down at the bottom that I'd love to use 
but it would need some new language features.

http://arrayboundserror.blogspot.com/2009/05/serialization-for-d-part-5-of-n.html

As always: Comments, Please! (particularly on the "feature request")