Fix duplicate attributes from SimulationManagementFamilyPdu (DIS 7)

[tzneal]

Remove the duplicate originating/receiving IDs as they are already part of SimulationManagementFamilyPdu

[leif81]

Maybe those duplicate fields should be removed from all pdu's that inherit from SimulationManagementFamilyPdu?

e.g. CreateEntityPdu, RemoveEntityPdu, StopFreezePdu, AcknowledgePdu, ActionRequestPdu, ActionResponsePdu, should have it removed to.

[mcgredonps]

I think that error rippled through all the SimulationManagment family PDUs--it's in the SimulationManagementFamilyPdu class, and everything that inherits from that also has those fields incorrectly repeated.

[mcgredonps]

There's a SimulationManagementHeader object defined in the standard, which is just the regular PDU header plus the two identifier fields. It's defined earlier in the XML file. I don't think it's worthwhile to reuse that here, since it would make for a special case in the inheritance chain. Better to just remove the duplicate fields in the subclasses.

[tzneal]

I cleaned up the other sim family PDUs and also removed a duplicate PDU that I noticed.

[leif81]

Nice. Looks good to me.