Replace `check_for_get_code` with `assert_request_status_code`

More flexible, uses the word "assert", method instead of function
Added enrollment breakdown by certificate track
Updating ORA2 hash for hotfix August 5th, 2014
Merge pull request #4709 from edx/ora2/hotfix-2014-8-5

Updating ORA2 hash for hotfix August 5th, 2014
add space to table header
make expanding explanation accessible

LMS-11161
Toggle aria-expanded attribute
Implemented process_response method to clear requestcontext global variable in mako middleware.
LMS-6622
Request IFRAME API every time with https scheme.
Merge pull request #4718 from edx/cdodge/fix-visual-bug

add space to table header
Merge pull request #4719 from edx/waheed/lms6622-implemented-process-response-method-rc

Implemented process_response method to clear requestcontext global variable in mako middleware.
Separated August changes into new table in chg log
ORA2 hotfix 2014-08-06
Merge pull request #4722 from edx/will/ora2-hotfix-2014-08-06

ORA2 hotfix 2014-08-06
Catch InvalidKeyError in UserTagsEventContextMiddleware.

LMS-11189
Catch InvalidKeyError in static_tab view.

LMS-11189
Merge pull request #4678 from edx/usman/lms11189-user-api-middleware-exception-2

Catch InvalidKeyError in UserTagsEventContextMiddleware and static_tab view.
Merge pull request #4654 from edx/db/kill-check-for-code

Replace `check_for_get_code` with `assert_request_status_code`
Merge pull request #4602 from edx/db/expand-on-click-or-enter

make expanding explanation accessible
Fix inconsistent ui issues on discussion during blackout period
FOR-108