edx/edx-platform — pull request #2294 by cpennington (2014-01-24 15:50:05+00:00)
Title: Add the ability to dark-launch languages

To mark a language as dark-launched, add it to the DARK_LANGUAGES django conf
setting. To activate a dark-launched language, set he query parameter
`preview-lang` to the language code on any url.

[LMS-2045]
[LMS-2077]
[LMS-2076]