On this page about authenticated proxies on Windows 8, it says
The issues that are discussed in this article are scheduled to be resolved in Windows 8.1. For more information about Windows 8.1, visit this Windows 8.1 Preview website.
The 8.1 preview website talks about proxy auto discovery, but I am not on an enterprise network. I am on a university network behind an authenticated HTTP proxy, and as far as I can tell the university has not done any group policy magic. I have tried using the group policy editor to get the Store to work, but no luck.
How can I get the Store (and other Metro Apps) to work with the authenticated proxy on Windows 8.1?