Try to find GCC on OSX for OpenMP support.

def extract_gcc_binaries():
    """Try to find GCC on OSX for OpenMP support."""
    patterns = ['/opt/local/bin/g++-mp-[0-9].[0-9]',
                '/opt/local/bin/g++-mp-[0-9]',
                '/usr/local/bin/g++-[0-9].[0-9]',
                '/usr/local/bin/g++-[0-9]']
    if 'darwin' in platform.platform().lower():
        gcc_binaries = []
        for pattern in patterns:
            gcc_binaries += glob.glob(pattern)
        gcc_binaries.sort()
        if gcc_binaries:
            _, gcc = os.path.split(gcc_binaries[-1])
            return gcc
        else:
            return None
    else:
        return None