sslutil: issue warning when [hostfingerprint] is used Mercurial 3.9 added the [hostsecurity] section, which is better than [hostfingerprints] in every way. One of the ways that [hostsecurity] is better is that it supports SHA-256 and SHA-512 fingerprints, not just SHA-1 fingerprints. The world is moving away from SHA-1 because it is borderline secure. Mercurial should be part of that movement. This patch adds a warning when a valid SHA-1 fingerprint from the [hostfingerprints] section is being used. The warning informs users to switch to [hostsecurity]. It even prints the config option they should set. It uses the SHA-256 fingerprint because recommending a SHA-1 fingerprint in 2017 would be ill-advised. The warning will print itself on every connection to a server until it is fixed. There is no way to suppress the warning. I admit this is annoying. But given the security implications of sticking with SHA-1, I think this is justified. If this patch is accepted, I'll likely send a follow-up to start warning on SHA-1 certificates in [hostsecurity] as well. Then sometime down the road, we can drop support for SHA-1 fingerprints. Credit for this idea comes from timeless in issue 5466.

setup: use setuptools on Windows (issue5400) We've had a long, complicated history with setuptools. We want to make it the universal default. But when we do, it breaks things. `python setup.py build` is broken on Windows today. Forcing the use of setuptools via FORCE_SETUPTOOLS=1 unbreaks things. Since the previous bustage with making setuptools the default was on !Windows, it seems safe to move ahead with the setuptools transition on Windows. So this patch does that.