Merge master

common/djangoapps/external_auth/views.py

common/lib/capa/capa/templates/filesubmission.html

common/lib/capa/capa/templates/textbox.html

common/lib/xmodule/xmodule/css/capa/display.scss

common/lib/xmodule/xmodule/css/sequence/display.scss

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

common/lib/xmodule/xmodule/modulestore/search.py

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

...lib/xmodule/xmodule/modulestore/tests/test_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/lib/xmodule/xmodule/stringify.py

common/lib/xmodule/xmodule/tests/test_export.py

common/lib/xmodule/xmodule/tests/test_import.py

common/lib/xmodule/xmodule/tests/test_stringify.py

common/lib/xmodule/xmodule/x_module.py

common/test/data/full/chapter/Overview.xml

common/test/data/full/video/welcome.xml