class I18n::ExceptionHandler

Note that the exception handler is not called when the option :throw was given.
was caught the handler returns an error message string containing the key/scope.
MissingTranslationData exceptions are re-thrown. When a MissingTranslationData
Handles exceptions raised in the backend. All exceptions except for

def call(exception, locale, key, options) 

def call(exception, locale, key, options)
  case exception
  when MissingTranslation
    exception.message
  when Exception
    raise exception
  else
    throw :exception, exception
  end
end