setup: only allow Python 3 from a source checkout (issue5804) People are running `pip install Mercurial` with Python 3 and that is working because not everything performs a Python version compatibility check. Modern versions of pip do recognize the "python_requires" keyword (https://packaging.python.org/tutorials/distributing-packages/#python-requires) which we set if using setuptools. But this isn't set nor recognized everywhere. To prevent people from accidentally installing Mercurial with Python 3 until Python 3 is officially supported, have setup.py fail when run with Python 3. But don't fail if we're running from a source checkout, as we don't want to anger Mercurial developers hacking on Python 3 nor Mercurial's test automation running from source checkouts. People running setup.py from source checkouts could still fall through a Python 3 crack. But at least the `pip install Mercurial` attempt will get nipped in the bud.

tests: add HTTP POST and PUT support to the $LOGDATE$ substitution The lfs serving code uses both POST and PUT requests (and there's existing support for POST).

py3: make regex bytes in hgweb/webcommands.py # skip-blame because just b'' prefix

py3: replace types.NoneType with type(None) types.NoneType is not present in Python 3.

py3: add missing b'' in test-arbitraryfilectx.t # skip-blame as just b'' prefix

py3: pass ctx.rev() instead of ctx in range()

py3: add b'' prefixes in test-alias.t # skip-blame as it's just b'' prefixes

py3: add b'' prefixes in test-revset.t # skip-blame because it's just b''

py3: make sure we use bytes in generate-working-copy-states.py

py3: fix keyword arguments handling in hgext/acl.py # skip-blame because we added r'' prefixes