Update namespace-package eggs and tests to work under Python3, too.
Update .spec- and .toc-files for namespace-package tests.
Add `is_py33` flag.
Add test-case for PEP 420 namespace packages (requires Python >= 3.3).
Make runtest.py keep the .spec-files for the namespace-pkg tests.
Update .gitignore:

* ignore /tests/... (was still /buildtests/...)
* ignore /dist/, too
* ignore directories, where directories are meant
* changes /e2etests to /old/e2etests (was moved there)