Merge pull request #2559 from edx/usman/lms2136-wiki-access

cms/djangoapps/contentstore/tests/test_contentstore.py

cms/djangoapps/contentstore/views/course.py

common/lib/xmodule/xmodule/course_module.py

common/lib/xmodule/xmodule/modulestore/mixed.py

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

common/lib/xmodule/xmodule/modulestore/split_mongo/split.py

...odule/xmodule/modulestore/tests/test_mixed_modulestore.py

common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py

common/lib/xmodule/xmodule/modulestore/tests/test_xml.py

common/lib/xmodule/xmodule/modulestore/xml.py

common/lib/xmodule/xmodule/modulestore/xml_importer.py

common/test/data/two_toys/course/TT_2012_Fall.xml

lms/djangoapps/course_wiki/tests/test_access.py

lms/djangoapps/course_wiki/utils.py