GPII-158: Modify simplify enactor to use a selector of elements to hide, rather than duplicating the article element; add selector to necessary elements in demo content
GPII-158: Pass elements and model value to simplfy enactor set() method.
Merge remote-tracking branch 'anastasia/GPII-158'

* anastasia/GPII-158:
  GPII-158: Pass elements and model value to simplfy enactor set() method.
  GPII-158: Modify simplify enactor to use a selector of elements to hide, rather than duplicating the article element; add selector to necessary elements in demo content