Problem creation l10n

Conflicts:
	common/lib/xmodule/xmodule/capa_module.py
	common/lib/xmodule/xmodule/master_class_module.py
	common/lib/xmodule/xmodule/peer_grading_module.py
i18n problems
Merge branch 'feature/xmodule-i18n' of https://github.com/smartdec/edx-platform into feature/xmodule-i18n

Conflicts:
	common/lib/xmodule/xmodule/capa_module.py
	common/lib/xmodule/xmodule/templates/problem/drag_and_drop.yaml