STUD-1911, STUD-1932: Publish sections, subsections and units from course outline.
Merge pull request #4750 from edx/anton/publish-unit-from-course-outline

Publish sections/subsections/units from course outline.
Studio: correcting font weight/display issues

* reducing font-weight on component adding menu
* adding in and applying demi-strong font-weight
* adding in $color-copy-emphasized variable
* correcting stateful xblock settings styling nesting
* syncing video player xblock-based controls font-weight

STUD-2109
Update bok-choy version
Fix Studio to gracefully handle xblock JavaScript errors

TNL-46

I've changed Studio to catch JavaScript errors when rendering xblocks, log the error, but to then continue as normal. This means that the user is still able to interact with the xblock to delete, duplicate etc. This seems reasonable as the xblock is only rendered as a WYSIWYG representation so if it isn't fully interactive that shouldn't be a big problem.