- reverted back to distutils since we weren't using it for anything except for unit tests...
- replaced 'build_ext' command with a custom one
- setup.py should now work as long as some version of cython is installed
- command line options to build_ext only work if matching versions are installed
- note: a cleaner solution would be to force matching python and cython versions,
  but certain linux distros (ubuntu) don't yet come packaged with correct versiosn
  of cython