Remove translation strings from assessment APIs
Updated logging in XBlock mixins
Added more verbose logging in assessment APIs
Cleaned up i18n strings in templates.
Add missing i18n strings
Add i18n to Travis build
Remove fake2 language, since we already have Esperanto
Merge pull request #408 from edx/will/i18n-strings-cleanup

i18n string cleanup
Use external submissions API
Move openassessment out of the apps directory
Use pkg_resources to check whether OA XBlock is installed.