Fix for non-ASCII characters in LANGUAGES.name

https://github.com/divio/django-cms/issues/1803
Signed-off-by: Martin Koistinen <mkoistinen@gmail.com>
Use force_unicode() instead of plain unicode()
Fix tests
Merge pull request #2186 from yakky/feature/fix_1803

Fix for non-ASCII characters in LANGUAGES.name

Fix #1803 
Fix #2048