Move index code into index.js.
enable tender

This reverts commit 96485694d32a1f34a0a5f30dea71a75e86b795a6.
Rename contentstore/views/requests to helpers

This has caused confusion, since this file gets imported when trying to
import the requests library.  And besides, how was this file about
requests in the first place?  Helpers is a much better name.
Check for exceptions when rendering studio and students views.

        Otherwise it's possible to reach stuck states.
leveraging some of the existing notification styling for component errors in studio
Added acceptance tests for get_html exception handling

Make tests conform to new import UI
additional copy and styling for component syntax error in studio
Review fixes
fixing alignment error on studio component error message, i18n error message
Review fixes
Review fixes
Merge pull request #1353 from edx/ned/rename-requests

Rename contentstore/views/requests to helpers
Merge pull request #1350 from edx/db/enable-tender

re-enable tender
Merge pull request #1133 from edx/jkarni/fix/customtag-error

Jkarni/fix/customtag error
Wait for non-blank link in course-overview test
Fix styles.
Fix BLD-165.
Add a11y.
Fix js unit tests.
Change aria-label attribute to title.