User Avatars now available

[Orion Pobursky]

I've enable the use of user avatars. You can upload a 100px by 100px image of your choices at Control Center -> Avatars. As always, avatars must conform to the usage guidelines (i.e. be in good taste). You can also turn off the viewing of avatars at the same location list above.

Side notes:
- I think 100 by 100 might be to big for my taste but I go with it for now.
- Don't ask me to enable gif images. I turned them off on purpose to preclude animated images.