Conflicts:
	mwclient/listing.py

Quite silly, but until the problem is fixed on the server side,
it seems like this workaround is the best solution there is.

Prepare for Python 3.x support
- Use print function
- Use compability methods from six

Back-ported to Python 2.6 and 2.7

Conflicts:
	RELEASE-NOTES.md

Filtering links by namespace not working

- If database lag exceeds max lag, the API will still send 200, not 503.
  This was only added to documentation after bugzilla:31156.
  Ref. <https://www.mediawiki.org/wiki/Manual:Maxlag_parameter>
- In addition, Requests doesn't raise an exception when status code != 200
  unless raise_for_status() is called, so we should call that to catch
  any other 5xx errors such as Squid errors.
- Replace print statements with logging

Note that responses>=0.3.0 is needed to run the test suite now

As suggested in #52
Original auth mechanism introduced in #27
This change should retain backwards compability

fixed link in user-agent section

reStructuredText is quite picky

Added instructions for changing default user-agent

Added instructions and an example for changing the default user-agent,
as in: https://meta.wikimedia.org/wiki/User-Agent_policy .

Use new token handling system described on
https://www.mediawiki.org/wiki/API:Meta#tokens for MediaWiki >= 1.24

Work in progress, looks a bit dirty right now