Make pygments unconditional, it is required by setup.py anyway.
Override the current-directory local "docutils.conf" location with the Sphinx srcdir.
Fix a few missing Unicode/bytes filename problems.
Complete test suite overhaul.

* rename a few test modules to make the names more consistent

* do not copy/use Sphinx from build/ (unnecessary without 2to3)

* use a temporary dir for *all* test projects, the source tree
  will stay pristine that way  (default is tests/build)

* speed up tests by ~3x by splitting up test projects and avoiding
  rebuilds

--HG--
rename : tests/root/doctest.txt => tests/roots/test-doctest/doctest.txt
rename : tests/root/versioning/added.txt => tests/roots/test-versioning/added.txt
rename : tests/root/versioning/deleted.txt => tests/roots/test-versioning/deleted.txt
rename : tests/root/versioning/deleted_end.txt => tests/roots/test-versioning/deleted_end.txt
rename : tests/root/versioning/index.txt => tests/roots/test-versioning/index.txt
rename : tests/root/versioning/insert.txt => tests/roots/test-versioning/insert.txt
rename : tests/root/versioning/insert_beginning.txt => tests/roots/test-versioning/insert_beginning.txt
rename : tests/root/versioning/insert_similar.txt => tests/roots/test-versioning/insert_similar.txt
rename : tests/root/versioning/modified.txt => tests/roots/test-versioning/modified.txt
rename : tests/root/versioning/original.txt => tests/roots/test-versioning/original.txt
rename : tests/test_build_base.py => tests/test_catalogs.py
rename : tests/test_py_domain.py => tests/test_domain_py.py
rename : tests/test_rst_domain.py => tests/test_domain_rst.py
rename : tests/test_env.py => tests/test_environment.py
rename : tests/test_autosummary.py => tests/test_ext_autosummary.py
rename : tests/test_coverage.py => tests/test_ext_coverage.py
rename : tests/test_doctest.py => tests/test_ext_doctest.py
rename : tests/test_intersphinx.py => tests/test_ext_intersphinx.py
rename : tests/test_linkcode.py => tests/test_ext_linkcode.py
rename : tests/test_napoleon.py => tests/test_ext_napoleon.py
rename : tests/test_napoleon_docstring.py => tests/test_ext_napoleon_docstring.py
rename : tests/test_napoleon_iterators.py => tests/test_ext_napoleon_iterators.py