* updating vendor files
* updating class syntax (to new FA-based classes) for all UI elements
* correcting broken tests

This is the changes for STUD-1244, which introduces the ability for Studio to display
arbitrarily nested xblocks. In this change, a new container page is introduced which can
display nested xblocks. In particular, the xblock type of 'vertical' is special cased
to be shown inline as a collapsible section. The unit page is mostly unchanged, except
that container xblock's are shown as a link to their container page, rather than being
shown inline.

removed symbolset, replaced with fontawesome for alerts, notifications, and all references in js files