Merge branch 'master' into release

AUTHORS

cms/djangoapps/contentstore/features/component.feature

cms/djangoapps/contentstore/features/component.py

cms/djangoapps/contentstore/git_export_utils.py

cms/djangoapps/contentstore/management/commands/export.py

...ps/contentstore/management/commands/export_all_courses.py

cms/djangoapps/contentstore/management/commands/import.py

...entstore/management/commands/tests/test_cleanup_assets.py

cms/djangoapps/contentstore/management/commands/xlint.py

cms/djangoapps/contentstore/tests/test_contentstore.py

cms/djangoapps/contentstore/tests/test_course_settings.py

cms/djangoapps/contentstore/tests/test_import.py

cms/djangoapps/contentstore/tests/test_import_draft_order.py

cms/djangoapps/contentstore/tests/test_import_pure_xblock.py

cms/djangoapps/contentstore/tests/utils.py

cms/djangoapps/contentstore/views/course.py

cms/djangoapps/contentstore/views/entrance_exam.py

cms/djangoapps/contentstore/views/import_export.py

cms/djangoapps/contentstore/views/item.py

cms/djangoapps/contentstore/views/library.py