Only display active users for the certificate report

Also removes the unnecessary pre-fetch.
For certificate generations we will continue to generate certs for
both active and inactive users.

For the report we only display active users since it was confusing
due to the instructor dashboard only displaying active users.
Merge pull request #3261 from edx/jarv/limit-to-active-users

Only display active users for the certificate report
Refactored course_nav middleware to isolate the django-wiki hack,
remove unnecessary code, and clarify what it's doing.
Merge pull request #2775 from edx/dcs/wiki-no-middleware

Refactored course_nav middleware to isolate the django-wiki hack, remove unnecessary code, and clarify what it's doing.
Fix Chris Terman's email address
Update OpenID dialog text

We want to indicate more clearly that the information that we transmit
to the third party is governed by their terms of service and privacy
policy.
Merge pull request #3268 from edx/ned/fix-terman-name

Fix Chris Terman's email address
Merge pull request #3270 from edx/gprice/openid-dialog-text

Update OpenID dialog text
Implement editing from the Studio container page.

STUD-1306
Make tab name comparison case-insensitive
making chrome scroll up when showing the component menu on the Studio unit page
Refactor test logic for switching editor tabs
maintain scroll position after closing the component editing modal in Studio
small ui fixes in Studio - textbooks upload and loading font-size
removed edit-dialog and uploads css, changed component edit icon to pencil, small css fixes
Fix unit tests
fixed mixin sass
Changes based upon code review comments
Clean up the logic for the edit modal's title
Fix up edit_component so that it doesn't take an unnecessary step argument