Add an avatar URL in the user resource.
Review Request #3473 — Created Nov. 3, 2012 and submitted
Add an avatar URL in the user resource. User resources now list the URL representing the avatar for the user. This is a gravatar URL that does not specify a size. The caller can tack on accepted gravatar parameters to this URL to get the desired size and settings.
Unit tests pass. Checked the list and item resources for users and verified that valid gravatar URLs were listed.