Bug #1, Fix bug in JuxtaLearn Quiz scaffolding Javascript + CSS

* Stylesheet/ CSS - interim solution,
* JS - reset/ empty the scaffold area when all SB checkboxes unticked,
* Fix to "simple embed" WordPress plugin.
Bug #1, Fix to JuxtaLearn Quiz scaffolding - PHP/ HTML

* Create a tree-like structure, reduce repetition of taxonomy texts
Bug #1, More edits to JuxtaLearn Quiz scaffold styles/ CSS
Bug #3, Fix to "Simple Embed" WP plugin - "body_class" function
Bug #3, Translated user role in "Simple Embed" WP plugin
Merge branch 'juxtalearn' into jxl/CR8/api