Use some real templates in forum list view tests

Unfortunately, one template (thread-list-template, defined in
_thread_list_template.html) still relies on complex Mako processing, so
that is still being mocked in the tests.
Merge pull request #5046 from edx/andya/cohort-visibility-labels-2

Implement forum cohort visibility labels correctly
Merge pull request #5062 from Stanford-Online/jbau/shib-unicode

external_auth: handle request.META values as str, not unicode
Merge branch 'release'
Fixes to improve help experience& correct HTML build errors
Revert "Merge pull request #4976 from edx/will/ecom-128"

This reverts commit a03baee25cc1758193460190e8b16990dcf20767, reversing
changes made to 12e2d442e9bc3b919d36a9bad7d82ac27f01dd5c.
Bok choy test for cohort group label in post.
Merge pull request #5081 from edx/ahodges/doc/help_fixes

Fixes to improve help experience& correct HTML build errors
Merge pull request #5070 from edx/reruns/error-handling

Course Rerun: include stack trace in errors and Log errors.
Add i18n extraction test
Improve thread list view tests

An obsolete test case was passing because the assertions were too weak,
so the assertions are improved and the test case removed.
Temporarily disable bulk operations b/c old mongo
does too much work on exit and doesn't handle nesting
Merge pull request #5082 from edx/hotfix/2014-09-04

Revert "Merge pull request #4976 from edx/will/ecom-128"
Make primary button focus state more pronounced
increase contrast of submission_feedback text
Ensure forum nav cohort selector works correctly

One minor case is fixed (to pass "" instead of "all" as the group_id
parameter to indicate viewing all threads), and tests are added.
Update mongo counts.
Move more forum nav rendering logic to front end

The cohort selector is rendered only for a privileged user in a cohorted
course, and that logic is now in an Underscore template instead of Mako.
Corrections to guides for 4 Sep release

Items repaired:
- Pin_discussion.png file in wring directory
- Discussion_filters.png image in discussion_students unreadable,
replaced
- updated  release date in Research guide change log
- updated  release date in Course Author’s guide change log
- updated  “History” dates for fields added to research guide
remove course-id visual column from the list of coupons as it's useless information here and prevents overflows from happening