Also clarifies the contraction of location.course_id by throwing an exception for lcoations that are not of category course.

Add test for course_id method.

Features coming down the pipe will want to be able to:
* Refer to enrollments before they are actually activated (approval step).
* See what courses a user used to be enrolled in for when they re-enroll in
  the same course, or a different run of that course.
* Have different "modes" of enrolling in a course, representing things like
  honor certificate enrollment, auditing (no certs), etc.

This change adds an is_active flag and mode (with default being "honor").
The commit is only as large as it is because many parts of the codebase were
manipulating enrollments by adding and removing CourseEnrollment objects
directly. It was necessary to create classmethods on CourseEnrollment to
encapsulate this functionality and then port everything over to using them.

The migration to add columns has been tested on a prod replica, and seems to be
fine for running on a live system with single digit millions of rows of
enrollments.

Rename MITX_SETTING AUTOMATIC_AUTH_FOR_LOAD_TESTING -> AUTOMATIC_AUTH_FOR_TESTING because it will be used for acceptance testing also.

Remove _

Minor cleanup.

Remove unused course_filter page

removes university_profile urls and templates

removes all university_profile views

remove news from templates/index

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.)

Changed to subclassing django's PasswordResetForm and
overriding clean_password() instead of copy/paste.
Less lines to worry about for diff-cover this way =)

To following the link in the password reset email

* Changed unicode test cases to ascii encoding
* Removed 'stanford' hardcoding in TOS logic in lieu of
  'SHIB_DISABLE_TOS' MIT_FEATURES flag
* made 'external_auth' always an installed_app in lms
* log.exception changd to log.error where appropriate

But: did not change skipping tests to changing settings, for
reasons stated here:
https://github.com/edx/edx-platform/pull/67#issuecomment-19790330

As stipulated by Stanford's office of general counsel

Highlights:
* The url '/shib-login/' interfaces with apache/mod_shib via
  request.META to handle shibboleth login and registrations
* Courses can designate 'enrollment_domains' to limit enrollment
  to users with a linked ExternalAuthMap verified by a particular
  identity provider
* Tests
* Logging

 Changes to be committed:

	new file:   common/djangoapps/external_auth/migrations/0001_initial.py
	new file:   common/djangoapps/external_auth/migrations/__init__.py
	new file:   common/djangoapps/external_auth/tests/test_shib.py
	modified:   common/djangoapps/external_auth/views.py
	modified:   common/djangoapps/student/views.py
	modified:   common/lib/xmodule/xmodule/course_module.py
	modified:   lms/djangoapps/courseware/access.py
	modified:   lms/djangoapps/courseware/tests/test_access.py
	modified:   lms/envs/common.py
	modified:   lms/envs/dev.py
	modified:   lms/envs/test.py
	modified:   lms/templates/courseware/course_about.html
	modified:   lms/templates/dashboard.html
	modified:   lms/templates/extauth_failure.html
	modified:   lms/templates/navigation.html
	modified:   lms/templates/register.html
	modified:   lms/templates/signup_modal.html
	modified:   lms/urls.py
	renamed:    lms/wsgi_apache.py -> lms/wsgi_apache_lms.py

Make django use_tz

When a non-edX theme is enabled, then don't return anything for "top
news," which is edX-specific.