Add support for the JSON API

[GoogleCodeExporter]

In addition to the XML API that pydelicious supports, delicious also has a
JSON API for doing certain things:
http://del.icio.us/help/json/

Some of the functions are overlaps with what's in the XML, but some (like
url) are unique to JSON. None of the JSON functions seem to require
authentication, so it's pretty trivial to hack it up. The main value-add
would be choosing a JSON library so that delicious developers don't have to
think about that.

Before putting a lot of work into this it'd be nice to learn what the
development plans are for the delicious API.

Original issue reported on code.google.com by [email protected] on 17 Feb 2007 at 4:20