Possible bug in #snac:
* I create an avatar
* I set my avatar in the snac web UI
* I update my avatar (new image, same filename)
* I upload a new version of the avatar to the web UI
* snac still shows the old avatar
* I delete the avatar in the snac ui
* I upload a new version of the avatar to the web UI
* snac still shows the old avatar
* I copy the avatar to a new filename
* I upload the new version with a new filename to the web UI
* The new avatar shows up right away
* I create an avatar
* I set my avatar in the snac web UI
* I update my avatar (new image, same filename)
* I upload a new version of the avatar to the web UI
* snac still shows the old avatar
* I delete the avatar in the snac ui
* I upload a new version of the avatar to the web UI
* snac still shows the old avatar
* I copy the avatar to a new filename
* I upload the new version with a new filename to the web UI
* The new avatar shows up right away