Bug 103168

It would be nice to have a progress widget, similar to a JProgressBar but in
widget form.

In CASA we have a wait message in the form of a widget. It appears in the center
of the scene when a build is being performed. However, even better than a wait
message widget would be a progress bar widget. I like the idea of a progress bar
because it is a well-accepted way of showing animation when some kind of
processing is actively occurring. Having it be in the form of a widget provides
maximum flexibility - because the scene itself can contain the progress bar.

This is certainly not necessary, but it would be a nice widget to have as part
of the Visual Library.