Fixes for absolute_import and inop test failures on Windows.

1) absolute_import fails on Windows because it compiles nothing. The pattern passed to cythonize matches zero files.
cythonize's ``extended_iglob`` disregards Windows path separators yet it uses ``os.path.join`` that produces them.

2) one of inop tests fails on Windows Python 3.3, because it incorrectly uses ``Py_UNICODE`` type. (``Py_UNICODE`` is not guaranteed to be 4-byte even on 3.3)