Adds stanford-only icons in image download panels

Test object: vr496qy1015

![image](https://cloud.githubusercontent.com/assets/302258/4999366/7e83ebae-6996-11e4-9bf8-9befed87841c.png)
Are these not available on the object (e.g. `image.stanford_only` and `image.tooltip_text` ) similar to the height/width above?