[Distutils] wheel 0.24.0 released

[Daniel Holth]

The much-anticipated 0.24.0 release of wheel has occurred.

- The python tag used for pure-python packages is now .pyN (major version
  only). This change actually occurred in 0.23.0 when the --python-tag
  option was added, but was not explicitly mentioned in the changelog then.
- wininst2wheel and egg2wheel removed. Use "wheel convert [archive]"
  instead.
- Wheel now supports setuptools style conditional requirements via the
  extras_require={} syntax. Separate 'extra' names from conditions using
  the : character. Wheel's own setup.py does this. (The empty-string
  extra is the same as install_requires.) These conditional requirements
  should work the same whether the package is installed by wheel or
  by setup.py.

So we support and convert setuptools' conditional requiremenst to
METADATA. However, although
pkg_resources.working_set.by_key['wheel']._dep_map is correct, pip
install wheel[extraname] doesn't seem to work at all; this bug may be
fixed in an unreleased pip?

Daniel Holth