renamed:    io/__init__.py -> xio/__init__.py
renamed:    io/conll2/__init__.py -> xio/conll2/__init__.py
renamed:    io/conll2/conll_iter.py -> xio/conll2/conll_iter.py
renamed:    io/conll2/conll_reader.py -> xio/conll2/conll_reader.py
renamed:    io/conll2/conll_reader3.py -> xio/conll2/conll_reader3.py
renamed:    io/file_utils.py -> xio/file_utils.py
renamed:    io/file_utils3.py -> xio/file_utils3.py
new file:   xzip.py
xzip.gzip_open() is much faster than gzip.open()