Common Lisp bindings to the popular Gravatar service.

• size is an integer for the number of pixels along a side. Gravatar images are always square.
• default may be either a URL to your own image, or one of :404, :mm, :identicon, :monsterid, :wavatar, or :retro.
• force-default-p indicates whether to always use the default, even if another image is available. This is useful when you use a hash-based default like :identicon that is unique per user.
• rating may be one of :g, :pg, :r, or :x and indicates the level of "vulgarity" that you allow on your site. The default is :g.

This returns the cl-json formatted profile of the user. Eventually we'll parse this into better structures, but that is TBD.

If you want to process the profile data using client-side JavaScript, this generates a URL that you can use as a src value to the HTML script element. And the JavaScript function named by js-callback will be called on the resulting JSON data.

This returns an image URL for a QR code that encodes the URL of the user's profile page.