on "binding" the AD feature: where does the text go?

Hi,

Hugo just added some text to the bindings doc documenting how
the AD feature manifests itself in the HTTP case.

I'd like to suggest a different way of documenting how the AD
feature (and any binding implications of anything we put into the
predefined extensions document): include them in that document
itself. To make that more sensible, I'd like to reorder the parts:

part1: core language (as is)
part2: bindings (currently part3)
part3: predefined extensions (currently part2)

Since the dependency is circular we can't avoid forward refs but
IMO this ordering makes most sense because now we can have the
predefined extensions *fully* defined (including bindings of them)
in that document itself.

Sanjiva.