Packet state handling fails to properly initialize "dntoeu" values

[MJJoyce]

The current handling in get_packet_delta doesn't cache the dntoeu values for a given field.

        # get converted fields / complex fields
        packet_states[pkt_defn.name]['dntoeu'] = {}
        dntoeus = {}
        for f in pkt_defn.fields:
            if f.dntoeu is not None or f.enum is not None or f.type.name in dtype.ComplexTypeMap.keys():
                try:
                    val = getattr(ait_pkt, f.name)
                except ValueError:
                    if isinstance(f.type, dtype.CmdType):
                        val = "Unidentified Cmd"
                    else:
                        val = getattr(ait_pkt.raw, f.name)

                if isinstance(val, cmd.CmdDefn) or isinstance(val, evr.EVRDefn):
                    val = val.name

                dntoeus[f.name] = 

The dntoeu values are extracted and saved in dntoeus but packet_states isn't updated. It looks like this is causing the frontend to not get a proper set of dntoeu values on its initial request from the server. If these fields' raw values don't change then they get left as only raw values.