-Update from WebTranslator v3.0:
afrikaans - 5 changes by telanus
korean - 1 changes by telk5093
brazilian_portuguese - 26 changes by Tucalipe
slovak - 60 changes by Milsa


git-svn-id: http://svn.openttd.org/trunk@26669 6aa0318a-3be1-0310-93fa-89fd2396df07