Update travis.yml to test 1.2-1.4
Use transaction.commit_on_success as a decorator.

Django 1.2 does not support using transaction.commit_on_success as a
context manager, so we'll use it as a decorator.
Add a 1.2 compatible HttpRequest for testing.
Fix regression in 1.2 broken link mailing logic.
Added session-based authentication.
BACKWARD-INCOMPATIBLE: Dropping Django 1.2 support.
Hooray for typos.
Attempting to make TravisCI happy.
Another attempt at making TravisCI happy.
Added warning to docs regarding mod_wsgi and Authorization HTTP header with ApiKeyAuthentication. Fixes #587.
Make the possessive a plural. Thanks to @wolever for the issue and fix.
Added ``X-HTTP-Method-Override`` support, for situations where you can't use ``PUT/DELETE/PATCH``. Thanks to maraujop for the original patch!
Added docs & more tests for ``SessionAuthentication``.
Helps to finish the sentence.
Added a link to the CSRF+AJAX docs. Thanks to chrisdickinson for pointing that out!
Approved patches for fixing callable attributes on ToOneField and ToManyField. Thanks Donald Stufft and Valdimir Volodin for the fixes, and pennersr and sgarcez, for reports.

Closes #347
Closes #355
Closes #554
Closes #608
Closes #609
Fixed ``SessionAuthentication`` to only check CSRF on data-changing methods. Thanks to natmaster for the report!
Corrected ``Paginator.get_limit`` behavior when ``limit=0``.
Added mcu to AUTHORS.
Fixed ``Paginator`` appending multiple ``offset/limit`` values to querystring.