Cleanup pexp commands, remove direct settings import
Convert Django project files in the root to example project.

Move pexp project to 'example' folder too.
Remove polymorphic_dumpdata command and assorted scripts.

The polymorphic_dumpdata command carried a deprecation note for a long
time now. The scripts for testing python versions are replaced by tox already.
Add runtests script

Allow `python setup.py test` too.
Fix tox invocation now that `manage.py` has moved.
Use self.assertEqual() in tests instead of assert statement.
Replaced the doctests with unit tests

Making debugging tests much easier. The same repr() logic is preserved,
so this is essentually a huge coding style change.
Tests: remove Django 1.1 compatibility check
Tests: auto removed unused imports
Tests: make old code more readable
Tests: fix missed error in last commit

(cannot amend, already pushed for review)
Merge pull request #30 from vdboor/cleanup_for_15

Cleanup before porting to Django 1.5