Return a sort function for sorting header GO IDs found in sections.

def _get_fncsortnt(flds):
        """Return a sort function for sorting header GO IDs found in sections."""
        if 'tinfo' in flds:
            return lambda ntgo: [ntgo.NS, -1*ntgo.tinfo, ntgo.depth, ntgo.alt]
        if 'dcnt' in flds:
            return lambda ntgo: [ntgo.NS, -1*ntgo.dcnt, ntgo.depth, ntgo.alt]
        return lambda ntgo: [ntgo.NS, -1*ntgo.depth, ntgo.alt]