protobuf internal message for pose and state

[alfski]

I think a more complex protobuf will be needed... eg.

message CesiumSync {
  required int32 msgtype =1;
  optional CameraPose pose = 2;
  optional State state = 3;
  message CameraPose { 
    required sint32 lon;
    ... lat, alt, heading, pitch, roll all required
   }
  message State { // viewer state
     optional boolean fog = 1;
     optional boolean lighting = 2;
     optional string ImageryProvider = 3;  // "Bing.ROAD"
     optional string TerrainProvider = 4; // "STK"
     optional boolean showDebugFPS = 5;
     ...
  }
}