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

SASS compilation variable conventions update, focusing on basic colors, baseline variable usage for padding and margins, ui-depth extends, along with other small fixes. The intent with this is to not have any user-facing impact, and instead move us closer toward having files that use our newer sass conventions.

* 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

* adding back in drag and drop indicators to outline DOM
* correcting visual display of drag action in outline UI
* adjusting styling of outline drag and drop indicators
* adjusting styling of drag and drop was-dropped state

* correcting visual display of outline UI without content
* temporarily resolving page actions that should be hidden by default

cleanup of unit, container, and xblock sass; added modules and layout sass; publishing states and actions on new unit

STUD-1754

* provides new .scss file for developers to add temporary/in-progress Sass for further refactor/polish
* cleans up note/import order in shame and application Sass files

Also includes RequireJS changes.

Fixes bugs:
STUD-755, STUD-152, STUD-700, STUD-699

typography, SASS import, mixins/extends