Merge pull request #336 from MITx/feature/victor/xml-verify

common/djangoapps/xmodule_modifiers.py

common/lib/supertrace.py

common/lib/xmodule/lazy_dict.py

common/lib/xmodule/progress.py

common/lib/xmodule/xmodule/editing_module.py

common/lib/xmodule/xmodule/error_module.py

common/lib/xmodule/xmodule/errortracker.py

common/lib/xmodule/xmodule/html_checker.py

common/lib/xmodule/xmodule/html_module.py

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

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

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

common/lib/xmodule/xmodule/stringify.py

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

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

...dule/xmodule/tests/test_files/choiceresponse_checkbox.xml

...xmodule/xmodule/tests/test_files/choiceresponse_radio.xml

common/lib/xmodule/xmodule/tests/test_files/coderesponse.xml

...le/xmodule/tests/test_files/formularesponse_with_hint.xml

...on/lib/xmodule/xmodule/tests/test_files/imageresponse.xml