What's the story on

  http://ftp.squeak.org/4.5alpha/Squeak4.5-12641.zip

?  Is it the official alpha image I should be testing?  It's dated
only a couple of weeks ago.  Is this one from the CI build and had its
packages unloaded and reloaded?  If that's what we intend to release,
I'd like to start testing on that one.