> My first opinion when I have read the documentation was "but this doc is out of date".

Yes, some parts of the devguide is outdated and I already gave +1 to update those parts. But most of the other changes are use 3.4 as an example so changing it to 3.5 won't make the devguide up-to-date. For example,

    +must not be broken at any point between sibling minor releases (3.5.1, etc.).
    +For both rules, only rare exceptions are accepted and **must** be discussed
    +first.

and

    -while the maintenance branch names (``2.7``, ``3.4``, etc) are mapped
    +while the maintenance branch names (``2.7``, ``3.5``, etc) are mapped

>> It might also worth to update the build-dep command in setup.rst.
> I agree, I am going to check that

You've already changed setup.rst :) But it would great if you could test "sudo apt-get build-dep python3.5" and build Python on a modern Debian/Ubuntu since I'm still on 12.04.

It's very hard to point which parts are OK in the patch without Rietveld. I'll update it myself and attach here to save both of us some time :)

Thanks!