plone/plone.i18n — pull request #5 by jianaijun (2013-03-08 06:33:59+00:00)
Title: Fixed does not correctly handle client HTTP_ACCEPT_LANGUAGE is language/country combination issue.

Refer:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.10
http://www.gnu.org/software/gettext/manual/gettext.html#Locale-Names