[oe] QA Logs now on tinderbox

[Jeremy Lainé]

> But...why not fix these two immediately?

I have fixed python-pycairo, the problem here was that setup.py was
re-generating pycairo.pc every single time it was run, so patching the
file with sed did no good.

Instead we now generate pycairo.pc from pycairo.pc.in ourselves using sed.

Will look into Orbit-2.0.pc if I have a moment.

Cheers,
Jeremy