Add labels to the thumbnails in the 3 different viewers.
Toggle aria attributes when expanding/collapsing the popup panels.
Merge pull request #170 from sul-dlss/thumb-label

Add labels to the thumbnails in the 3 different viewers.
Merge pull request #171 from sul-dlss/aria-expand

Toggle aria attributes when expanding/collapsing the popup panels.
Add squash exception reporting support.