Proposal for enhanced metadata in (proposed) cgi-enhanced module

Regarding the "enhanced parameter support" idea mentioned in my previous
mail, what I have in mind is to provide a list of all expected
parameters as a struct in the CGI and pass it to apreq immediately after
initialization (after, so there's no API incompatibility issues).  The
struct would contain the parameter names (and possibly type
body/arg/cookie) as well as some additional metadata fields.  Currently
we're thinking of starting with 2 called "description" and "default".
Some use-cases for these extra bits of information would be:

* For interactive mode, replace the current prompts and allow for
default value to be set
* For non-interactive mode, allow 3rd party server-side software (think
CGI.pm) to read this metadata and automatically prepare an HTML form
suitable for use with the CGI.  (apreq obviously wouldn't be making
these widgets - just providing metadata).
* If we add metadata classes that can specify expected content type, we
can even provide some sort of rudimentary input validation; combined
with the CGI.pm idea above, this might be a big step toward unified
server/client validation routines, since both server and client side
validation routines can be automated based on this metadata.

Thoughts?

  Issac