If we do change it later, then we can update the readme accordingly.

- Increase version requirement from Python 2.4 to Python 2.6, and from MediaWiki 1.11 to 1.16
- Add three entries to release notes

- For some reason, 'pytest-cache' isn't found by setup.py if not
  specified explicitly in 'tests_require'
- Add tox.ini so tests can be run using tox if desired
- Update test to not be dependent on serialization

- A single command `python setup.py test` will now install test
  dependencies, make an in-place build and run the tests.
- The setup script now requires Setuptools. A message will be printed
  if it is not found.

- Adding note that 0.6.5 might not work with the latest MediaWiki versions
- Fix link to wiki

simplejson is now a requirement installed by easy_install, pip
or other toos. ReadMe was converted from MarkDown to reStructuredText
to make it usable at PyPI while still being supported by GitHub.