Added language selector in admin
Replace language_selector code in base.html by a templatetag {%
language_selector %}
Make language_selector display conditional to USE_I18N setting
As USE_I18N setting is set to True by default, I18N needs to be
explicitly set to False in settings.py to avoid displaying the language
selector
Also, if settings.LANGUAGES is not set, the selector will display all
Django available languages (per Django design)
 replace hardcoded /i18n/setlang by proper {% url 'set_language' %}
Modified templatetag language_selector to render an empty response when
set_language url is not enabled
Merge pull request #59 from mobula/master

Added language selector in admin