This avoids the METH_O function signature by default, since it does not match normal Python semantics. * Fix unicode name handling of no-args functions when allowing keywords. * Fix a crash when a keyword argument is passed to a function that does not allow them. Previously, the reported key name was not set and thus NULL. * Extend "always_allow_keywords" test to cover some edge cases. Some are commented out as they currently only work with the fastcall implementation.