Rebuild UI unclear

[annevk]

When you hit Rebuild there's no indication of that request succeeding. And in fact if you didn't know better you might end up clicking on Rebuild several times to try to get something going.

1. It would be good if after you click Rebuild there was some indication of success.
2. And if you then go back to the prior page it would be good if the Rebuild button was annotated in some way that makes it clear a rebuild is queued.