playframework/playframework — pull request #2619 by smola (2014-04-08 08:38:37+00:00)
Title: When PLAY_LANG is set; treat it as first accepted lang.

Instead of blindly taking the PLAY_LANG value into lang(),
we treat it as the most prioritary language for the user.
This way a user cannot set a language that is undefined for
the application.