This patch updates the ImageViewer example to use Multiple Threading.

When importing an image into the database, the example now fires off a
new
Thread, which imports the image in the background. This also means that
the application doesn't freeze on the user, and they can still browse
the
images in the database, while the upload is running.

This now makes the ImageViewer a true example on how to use Threads (the
threadtest class is just that - a test).

Peter