ICU would return a utf-16 (endian dependent) codec for unicode
which is very rarely what people want. In most cases, unicode is
encoded in utf8 these days, so return a utf8 codec for it.
Task-number: QTBUG-41998
Change-Id: I51ee758d520702b263a8b2011787eb1f3455ed96
Reviewed-by: Lars Knoll <lars.knoll@digia.com>