Revert "Ensure that tmpdir is unicode. Fixes #704."
Revert "Ensure that tmpdir is unicode. Fixes #704."

This reverts commit 857949575022946cc60c7cd1d0d088246d3f7540.

As we can see on https://github.com/pypa/setuptools/issues/709,
this breaks many things (easy_install C extensions, all py3.5 tests,
run with LANG=C).

So instead of fixing in a hurry all new bugs due to this, I propose to
revert this commit until all downsides of this change have been
investigated.

Related bug: https://github.com/pypa/setuptools/issues/709
Related bug: https://github.com/pypa/setuptools/issues/710
Related bug: https://github.com/pypa/setuptools/issues/712

pypa/setuptools,pypa/setuptools,pypa/setuptools