[Distutils] py2-none-linux_x86_64 tag

[Daniel Holth]

By popular demand, the development version of wheel now includes the
tag for packages that include a binary but don't need a particular
Python or ABI - for example, cffi or ctypes packages using dlopen.
It's just after the implementation-specific tags. There is not a flag
to get bdist_wheel to tag packages this way; you would have to rename
them to get wheels bearing the new tag.

The complete list on PyPy is currently

[('pp27', 'none', 'linux_x86_64'),
 ('pp27', 'none', 'any'),
 ('pp2', 'none', 'any'),
 ('pp26', 'none', 'any'),
 ('pp25', 'none', 'any'),
 ('pp24', 'none', 'any'),
 ('pp23', 'none', 'any'),
 ('pp22', 'none', 'any'),
 ('pp21', 'none', 'any'),
 ('pp20', 'none', 'any'),
 ('py2', 'none', 'linux_x86_64'),
 ('py27', 'none', 'any'),
 ('py2', 'none', 'any'),
 ('py26', 'none', 'any'),
 ('py25', 'none', 'any'),
 ('py24', 'none', 'any'),
 ('py23', 'none', 'any'),
 ('py22', 'none', 'any'),
 ('py21', 'none', 'any'),
 ('py20', 'none', 'any')]

I've also merged a contribution from  Benedikt Morbach that sorts the
generated metadata to make it deterministic, and have tagged some of
the previous released. If there are no complaints I'll probably
release as 0.25.0 in a few days.

Daniel Holth