[wix-users] WiX v4.0 Version Breaking Change

[Sean Hall]

All,

In the latest v4.0 build, we implemented the same version change that we
did in v3.10.  Instead of making the version Major.Minor.Build.0 (e.g.
4.0.4305.0), it is now Major.Minor.Revision.Build (e.g. 4.0.0.4506).  This
means that if v4.0.4305.0 (or earlier) is installed, it must be manually
uninstalled before installing a newer version.  This gives us the
flexibility to do minor releases when necessary and make it clear in the
version number that it is a minor release.

We also revamped our installer UI to mimic the new Appx Installer UI in
Win10 AU, thanks to Phill Hogland.  When an older build is already
installed, the new UI will display a message reminding you that you must
uninstall that older build first.

As a reminder, v4 is still under active development and is not considered
stable or production ready.  To run the build and see the new UI, go to
http://wixtoolset.org/releases/v4-0-0-4506/.

Thanks,
Sean Hall