Port module to python3

[fim]

Hello,

I've made an effort to port this module to python3. The work is not backwards compatible with Python2.X (mainly due to the deprecation of the cStringIO which would mean a lot of code duplication for supporting both versions) and is provided as-is.

I've tested the change and it seems to work as expected but any comments are welcome!

[vrasneur]

Hi @fim,

Thanks for the port to python3!

However, I don't have time to maintain the module anymore. I see that you already have released your port as a separate module: https://pypi.python.org/pypi/icapclient3

So, I don't think that merging your changes into the older module is really necessary.

Regards,

Vincent