allow build on system with LANG="C" by defaut

[pmakowski]

Please made the change to allow the build on distributions build systems like Mageia or Fedora without patches or hack

[SimonSapin]

Is this a problem on Python 2, 3, or both?

[pmakowski]

on Python 3, but the patch is ok for both

it is a common issue

without the patch :

+ /usr/bin/python3 setup.py build
Traceback (most recent call last):
  File "setup.py", line 7, in <module>
    path.join(path.dirname(__file__), 'cairocffi', '__init__.py')
  File "/usr/lib/python3.3/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 2453: ordinal not in range(128)

[SimonSapin]

Merged, thanks.