implemented acquire_localized text function
fixes against commit "implemented acquire_localized text function"
Refactor defaults to not have a hardcoded language

* Add default_language to GLSetting
* Add languages_enabled to GLSetting
* Reference GLSetting.error_reporting_* instead of using a hardcoded value
* Place the sample submission fields in settings.py
Major refactoring on multi language support in backend

* Use a smarter pattern for nesting values inside the lang code key
* Uniform the arguments that transact decorated functions take and pass a
  default argument to them
* Fix unittests to work with the new code