Merge pull request #4853 from edx/christina/stud-2093

cms/djangoapps/contentstore/views/item.py

cms/djangoapps/contentstore/views/preview.py

common/djangoapps/xmodule_modifiers.py

common/lib/xmodule/xmodule/js/src/conditional/display.coffee

common/lib/xmodule/xmodule/js/src/sequence/display.coffee

common/lib/xmodule/xmodule/public/js/split_test_staff.js

common/static/coffee/spec/xblock/core_spec.coffee

common/static/coffee/src/xblock/core.coffee

lms/djangoapps/courseware/module_render.py

lms/djangoapps/courseware/tests/test_module_render.py

lms/djangoapps/instructor/views/instructor_dashboard.py

lms/djangoapps/instructor/views/legacy.py

lms/djangoapps/instructor_task/tasks_helper.py