Bug 566: Create Artifact Loads the Wrong Image

Code Review: http://mrccodereview.cloudapp.net/ui#review:id=1267

This was discussed with Peter/Roman: SeaDragon images are causing more trouble than benefit due to new authoring feature:
a) They take too long to load
b) Encoded URLs maliciously crafted can show users unexpected images

Therefore, we are removing SeaDragon images except for the AIDS-Quilt timeline.