bpo-32507: Change Windows install to include app-local UCRT

[zooba]

Also fixes bpo-29911, which I forgot about until after I'd already fixed and committed the change.

https://bugs.python.org/issue32507

[zooba]

I can't seem to trigger an AppVeyor build - @zware?

[zware]

I'm going to remove the file whitelist in the AppVeyor config; I think it's causing us more hassle than it's worth. They only check the HEAD commit rather than the difference against the base branch, so since your last commit only changes NEWS entries, AppVeyor doesn't think it should run.

In the meantime, I'll manually start another build here (which you should also be able to do by logging into AppVeyor as the python user). Then again, since it's never run a build on this PR, I can't. Killing the whitelist now...

[zooba]

I tried logging in, but I could only re-run existing PRs. Because it never picked this one up, I couldn't start it.