fix several issues in setup.py and make pkgconfig evaluation more Py3 compatible
fix several issues in setup.py and make pkgconfig evaluation more Py3 compatible

--HG--
extra : rebase_source : ba06ec7166cae40cb8eae5cddce5e91749f8d694

pombredanne/lupa,jleni/lupa,tuyendothanh/lupa,tuyendothanh/lupa,pombredanne/lupa,jleni/lupa