Merge pull request #7262 from edx/cale/xblock-filtered-children-tests

cms/djangoapps/contentstore/views/preview.py

common/lib/xmodule/xmodule/course_module.py

common/lib/xmodule/xmodule/modulestore/__init__.py

common/lib/xmodule/xmodule/modulestore/mongo/base.py

common/lib/xmodule/xmodule/tests/__init__.py

common/lib/xmodule/xmodule/tests/test_conditional.py

common/lib/xmodule/xmodule/tests/test_library_content.py

common/lib/xmodule/xmodule/tests/test_split_test_module.py

common/lib/xmodule/xmodule/x_module.py

lms/djangoapps/courseware/model_data.py

lms/djangoapps/courseware/module_render.py

lms/djangoapps/courseware/tests/test_courses.py

lms/djangoapps/courseware/tests/test_module_render.py

lms/djangoapps/courseware/tests/test_views.py

lms/djangoapps/courseware/views.py

lms/djangoapps/lms_xblock/field_data.py

requirements/edx/github.txt