[pypy-dev] have pypy active branches use py.lib 1.0 final

[Samuele Pedroni]

Given that py.lib 1.0 final is out, I think it makes sense to switch 
pypy active branches starting from trunk to use an external pointing to 
that.

There are going to be some changes and possibly issues that will need 
addressing, the work may need to happen on a branch at first.

I plan to work on this middle of next week if there are no objections.

Samuele

PS: the window buildbot is also down, given that we host it we will look 
into that