Fix QName.compareTo() logic

QName implements Comparable<QName> contract with the following logic:

    public int compareTo(final QName o) {
        int result = getLocalName().compareTo(o.getLocalName());
        if (result != 0) {
            return result;
        }
        return module.compareTo(o.module);
    }

this has very ugly implications, as QNames are grouped by their localName first and then by their namespace.

This is counter-intuitive as namespace is really what is grouping concerns, hence we should keep things in the namespace neatly together.