Merge pull request #37 from cam-stitt/master

Add pip instructions to Readme. Decode strings.
Fix issue with decoding exceptions.
Merge pull request #40 from justinabrahms/decode-error-fix

Fix issue with decoding exceptions.
Merge branch 'master' of git://github.com/joestump/django-ajax
Authentication now uses a base class. Add AJAX_AUTHENTICATION setting.