Open demo realm automatically

[astigsen]

When choosing to download a demo realm, it should be opened automatically after the download has completed (you might not have noticed which folder it was downloaded to).

Maybe the text should then be "New to Realm. Download and open a demo Realm file".

It would also be nice with some kind of progress indicator while it downloads.

[ironage]

+1 for progress notification. I downloaded the demo realm on a slow connection and tried to open it before it was finished which gives a "bad size" error.

I notice that the demo realm is 9MB which is pretty big - when I open it up in a hex editor I see lots of free space which indicates that compacting it could produce a much smaller file. We should link to a compact version which would mitigate this problem.