pylint (using Python 2.7) got propagated into python3Packages.spyder
so Python 2.7 setup-hook was used instead of python34.
Now that pylint is part of pythonPackages attribute set, pylint is
used with python3.4 as a base.
It doesn't make sense to build tools/applications with three different
python interpreter versions, so move them out of python modules list.
Also reverts 53ffc6e0ef.