[cairo] Buffer interface for pycairo

[Paul Colomiets]

Hi,

I've implemented buffer interface for ImageSurface for python3.
Including get_data and create_for_data methods. It's based on work by
Jeremy Moles few month ago, but fixes memory leaks (and adds few
scripts to test that). The code is here:

https://github.com/tailhook/pycairo

So:

1. What is the preferred way for contibuting. Send patches into
mailing list? Or can you just pull from my repo?
2. Should it be single patch or including history?
3. Should we include test files for memory leaks? (may not work on windows)

-- 
Paul