Provide a context to the uploader demo

In order to gather more accurate results from the user testing, the Uploader demo requires a concrete context. I suggest we add a mock Sakai Resources screen as a background (as we did with Inline Edit demo), and place the Add Files button somewhere on the screen. Ideally, I'd like the user to be able to see a list of files and see a highlighted group of files added to the list after the upload.