As an Exhibition user, I want to see a progress indicator of some sort when the View Metadata button is clicked.

When the cache is disabled in Exhibition, it could take several seconds or more to bring up the View Metadata popup page. But when the Exhibition is trying to process the View Metadata request, there is no progress indication like a spinning wheel to let the user know the work is in progress. This causes user to believe the request didn't go through and click multiple times instead of waiting for the response to come back.