Fix pylint/pep8 warnings, use JsonResponse instead of HttpResponse where useful,
put in TODOs to change HTTP status codes to be more accurate.

* Fix open redirect vulnerability
* Add Logging To AUDIT_LOG : Note I had to change existing tests
  that mocked AUDIT_LOG with this
* Use external_auth.views.SHIBBOLETH_DOMAIN_PREFIX in student.views
* Add a bunch of documentation
* PEP8 / Pylint

* If a shib users type in their email on the regular login page,
  redirects them to /shib-login/
* Modify student.views.accounts_login to handle redirects
  generated by @login_required for courses that use shib for
  access control.
  Redirect those logins to /shib-login/?next=

Add audit log definition, and use for logging of logins in external_auth and student apps.  Move test_login to student app. Improve conditional tests for Shibboleth login logic.  (Does not include reconfiguring log settings.)

when loaded by rake test_cms

I moved the test into lms/courseware/tests so they run correctly.

strings.

Added unit tests that verify the fix.