These tests currently fail on win32:

test_unicode_file    IN-PROGRESS: implement unicode filesystem.
                     (see branch/unicode_filename)
test_univnewlines    INCORRECT FIX: os.popen('echo 1') should not return
                     '1\r\n'
                     Either we cheat and give subprocess universalnewlines on windows in popen,
                     or we teach subprocess some impl specific things about windows,
                     or we revert to the old approach for non seekable streams if there's a sane way to detect that.