title: Wheel names are platform independent even though my package includes compiled libraries
body: <p>I'm trying to generate platform specific binary distribution packages for windows, but <code>python setup.py bdist_wheel</code> generates universal file names. What do I need to change in my setup.py or otherwise to get wheels with platform specific names?  From what I gather setuptools is supposed to recognize when a package will not be universal, but this is not working for me.</p>
  
  <p>The project I'm working on compiles several variants of libraries using cmake and mingw w64.  These compiled libraries are of course 32/64 bit specific.  To create the individual distributions I create a virtualenv for the target platform from which I compile the libraries.  The compiled libraries are then copied into the python package to be wheel'd.  </p>
  
  <p>Here is my setup.py. pyfvs_files is a list of compiled, '*.pyd' files to include. This produces wheels named 'pyfvs-0.0.1a0-py27-none-any.whl' where I would expect it to be 'pyfvs-0.0.1a0-py27-none-win32.whl' and 'pyfvs-0.0.1a0-py27-none-win_amd64.whl'.  When installed via pip the packages function as expected for the target platform, but of course fail for the alternate platform. Ultimately I'd like to support Python 2.7, 3.4, 3.5 on both windows 32 &amp; 64 bit and linux 64 bit.</p>
  
  <pre><code>import os
  from glob import glob
  
  from setuptools import setup
  from setuptools.dist import Distribution
  
  # TODO: Get the version from the git tag and or revision.
  version = '0.0.1a0'
  
  if os.name=='nt':
      so_ext = 'pyd'
  else:
      so_ext = 'so'
  
  pyfvs_files = glob('pyfvs/*.{}'.format(so_ext))
  pyfvs_files.extend(['pyfvs/pyfvs.cfg',])
  
  description = open('./README.txt').readline().strip()
  long_desc = open('./README.txt').read().strip()
  
  class BinaryDistribution(Distribution):
      def is_pure(self):
          return False
  
  setup(
      name='pyfvs'
      , version=version
      , description=description
      , long_description=long_desc
      , url=''
      , author=""
      , author_email=""
      , packages=['pyfvs',]
      , include_package_data=True
      , distclass=BinaryDistribution
      , data_files = [
              ('pyfvs',pyfvs_files)
              , ('pyfvs/docs',glob('pyfvs/docs/*'))
              , ('pyfvs/examples',glob('pyfvs/examples/*'))
              , ('pyfvs/test',glob('pyfvs/test/*'))
              ]
      , entry_points={
              'console_scripts': [
              'fvs=pyfvs.__main__:main'
              ]
          }
      , classifiers=[
              'Development Status :: 3 - Alpha'
              , 'Environment :: Console'
              , 'Intended Audience :: Developers'
              , 'Intended Audience :: End Users/Desktop'
              , 'Intended Audience :: Science/Research'
              , 'Natural Language :: English'
              , 'Programming Language :: Python'
              , 'Programming Language :: Fortran'
              ]
      , keywords=''
      )
  </code></pre>