Update course_navigation.html

The tab names are not being translated
Make remaining dialogs in wiki accessible.

All the dialogs in the wiki are now accessible to screen readers.

Also, the "Switch to selected version" button did the odd thing of
reloading the page with the new version selected, but inside a dialog.
That is now fixed.

The merge dialog has a warning that looks kind of funky still, but you
can read it, unlike the previous code.

LMS-1337
Update mode appropriately when user enrolls

The "mode" was remaining unchanged when a student unenrolled & re-enrolled in a course--i.e., someone who was verified when first registering would still be verified when unenrolling and re-registering in audit mode.  This commit fixes this problem.

LMS-1526
Upgrade coverage to 3.7
LMS: adds in collapse/expand UI for dashboard view upsell
Changed unit identifier to be readonly, not disabled

STUD-863
Studio: correcting hiding state of notification UI for < IE9
STUD-815
Fix unique vertical url + add test
STUD-979
Restful api for course advanced settings
STUD-948
Disabled video caption tests that failed in master
Studio: adding basic italicize text styling into xmodule/block preview UI
STUD-963
Disabled another video test that failed in master
cleaning up wiki sidebar double icons and updating to font-awesome elsewhere bug
UX-55
reverting changes to wiki edit and history pages
reverting changes to wiki edit and history pages again