LiveData: Initial implementation

Add support for live data subscription via Device::subscribeLiveData() and
Device::unsubscribeLiveData(). The live data API can be used to subscribe to
individual "signals", a full list of which can be found in LiveDataValueType.

include/icsneo/communication/message/livedatamessage.h

@@ -0,0 +1,44 @@
+#ifndef __EXTENDEDLIVEDATAMESSAGE_H_
+#define __EXTENDEDLIVEDATAMESSAGE_H_
+#ifdef __cplusplus
+
+#include <chrono>
+#include "icsneo/communication/message/message.h"
+#include "icsneo/communication/command.h"
+#include "icsneo/communication/livedata.h"
+
+namespace icsneo {
+class LiveDataMessage : public RawMessage {
+public:
+	LiveDataMessage() : RawMessage(Message::Type::LiveData, Network::NetID::ExtendedCommand) {}
+	LiveDataHandle handle;
+	LiveDataCommand cmd;
+};
+
+class LiveDataCommandMessage : public LiveDataMessage {
+public:
+	LiveDataCommandMessage() {}
+	std::chrono::milliseconds updatePeriod;
+	std::chrono::milliseconds expirationTime;
+	std::vector<std::shared_ptr<LiveDataArgument>> args;
+	void appendSignalArg(LiveDataValueType valueType);
+};
+
+class LiveDataValueMessage : public LiveDataMessage {
+public:
+	LiveDataValueMessage() {}
+	uint32_t numArgs;
+	std::vector<std::shared_ptr<LiveDataValue>> values;
+};
+
+class LiveDataStatusMessage : public LiveDataMessage {
+public:
+	LiveDataStatusMessage() {}
+	LiveDataCommand requestedCommand;
+	LiveDataStatus status;
+};
+
+} // namespace icsneo
+
+#endif // __cplusplus
+#endif // __EXTENDEDLIVEDATAMESSAGE_H_