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

def _init_fncsortnt(flds):
        """Return a sort function for sorting header GO IDs found in sections."""
        if 'tinfo' in flds:
            if 'D1' in flds:
                return lambda ntgo: [ntgo.NS, -1*ntgo.tinfo, ntgo.depth, ntgo.D1, ntgo.alt]
            else:
                return lambda ntgo: [ntgo.NS, -1*ntgo.tinfo, ntgo.depth, ntgo.alt]
        if 'dcnt' in flds:
            if 'D1' in flds:
                return lambda ntgo: [ntgo.NS, -1*ntgo.dcnt, ntgo.depth, ntgo.D1, ntgo.alt]
            else:
                return lambda ntgo: [ntgo.NS, -1*ntgo.dcnt, ntgo.depth, ntgo.alt]
        else:
            return lambda ntgo: [ntgo.NS, -1*ntgo.depth, ntgo.alt]