Unique Avatar URLs

[ZiNgA BuRgA]

An issue I've encountered at times is with uploaded avatars and browser caches.

Let's say, a user uploads a PNG avatar.
Two weeks later, they upload another PNG avatar.  However, when they finish uploading it, they see their old avatar!
This is because the browser is caching their old avatar - a simple page refresh fixes it, however, other users may see the old avatar...

...and, users aren't always that intelligent.

This simple plugin forces avatar upload URLs to be unique, thus, forcing the browser to reload the avatar, whenever it's changed.